CHAPTER EIGHT Statistical Inference: Estimation for Single Single Populations Populations B
1.
M Term Term
A
2.
Term Term
When When a sta stati tist stic ic calc calcul ulat ated ed from from samp sample le data data is used used to esti estima mate te a population parameter, it is called _______. _______. A. B. C. D.
an interval estimate a point estimate a statistical parameter a good guess
Whe When a range ange of val valu ues is use used d to to est estim imat ate e a popula pulati tion on parameter, it is called _______. A. B. C. D.
an a n interval estimate a point estimate a statistical parameter a range estimate
2!1
2!2 Test Ba Ban" A #. Ca Cath ther erin ine e Cha Chao o, Dir Direc ecto torr of of Mar Mar" "etin eting g $es $esea earrch, ch, is is eva evalu luat atin ing g consumer acceptance acceptance of a ne% ne% toothpaste pac"age. pac"age. &er sta' reports reports that 1() of a random sample of 2!! households prefer the ne% pac"age pac"age to all other other pac"age designs. *f Catherine concludes concludes that 1() of all households prefer the ne% pac"age, she is using a _______. M BApp
A. B. C. D.
D
Bria Brian n an anec ece" e",, - of of per perat atio ions ns at -ortla rtland nd Trust rust Ban Ban", ", is evaluating the service level provided to %al"/in customers. Accordingl0, Accordingl0, his sta' recorded recorded the %aiting times for + randoml0 selected %al"/in customers, and calculated that their mean %aiting time %as %as 1 minutes. *f Brian concludes that the the average %aiting time for all %al"/in customers is 1 minutes, he is using a ________. ________.
+.
a point estimate a range estimate a statistical parameter an interval estimate
M BApp
A. B. C. D.
C
ug ugene ene a ates, tes, Ma Marr"eti eting Dire irector ctor of Ma Man ns3el s3eld d Mo Motors tors Manufacturers, Manufacturers, *nc.4s lectrical Division, is leading a stud0 to assess the relative relative importance of of product product features. An item on a surve0 5uestionnaire distri6uted distri6uted to 1!! of Mans3eld4s customers as"ed them to rate the importance of 7ease of maintenance8 on a scale of 1 to 1! 9%ith 1 meaning 7not 7not important8 and 1! meaning 7highl0 7highl0 important8:. &is sta' assem6led assem6led the follo%ing follo%ing statistics. ase of Maintenance Maintenance Mean (. ;tandard 1. De via tio n *f ugene concludes that the average rate of 7ease of maintenance8 for all all customers is (., (., he is using ________. ________.
.
M BApp
a range estimate a sta statisti stical para arameter an interval estimate a point estimate
A. ar arange estimate B. a sta statisti stical para arameter
2!2 Test Ba Ban" A #. Ca Cath ther erin ine e Cha Chao o, Dir Direc ecto torr of of Mar Mar" "etin eting g $es $esea earrch, ch, is is eva evalu luat atin ing g consumer acceptance acceptance of a ne% ne% toothpaste pac"age. pac"age. &er sta' reports reports that 1() of a random sample of 2!! households prefer the ne% pac"age pac"age to all other other pac"age designs. *f Catherine concludes concludes that 1() of all households prefer the ne% pac"age, she is using a _______. M BApp
A. B. C. D.
D
Bria Brian n an anec ece" e",, - of of per perat atio ions ns at -ortla rtland nd Trust rust Ban Ban", ", is evaluating the service level provided to %al"/in customers. Accordingl0, Accordingl0, his sta' recorded recorded the %aiting times for + randoml0 selected %al"/in customers, and calculated that their mean %aiting time %as %as 1 minutes. *f Brian concludes that the the average %aiting time for all %al"/in customers is 1 minutes, he is using a ________. ________.
+.
a point estimate a range estimate a statistical parameter an interval estimate
M BApp
A. B. C. D.
C
ug ugene ene a ates, tes, Ma Marr"eti eting Dire irector ctor of Ma Man ns3el s3eld d Mo Motors tors Manufacturers, Manufacturers, *nc.4s lectrical Division, is leading a stud0 to assess the relative relative importance of of product product features. An item on a surve0 5uestionnaire distri6uted distri6uted to 1!! of Mans3eld4s customers as"ed them to rate the importance of 7ease of maintenance8 on a scale of 1 to 1! 9%ith 1 meaning 7not 7not important8 and 1! meaning 7highl0 7highl0 important8:. &is sta' assem6led assem6led the follo%ing follo%ing statistics. ase of Maintenance Maintenance Mean (. ;tandard 1. De via tio n *f ugene concludes that the average rate of 7ease of maintenance8 for all all customers is (., (., he is using ________. ________.
.
M BApp
a range estimate a sta statisti stical para arameter an interval estimate a point estimate
A. ar arange estimate B. a sta statisti stical para arameter
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 2!# C. a point estimate D. an interval estimate
2!+ Test Ban" A >. ugene ates, Mar"eting Director of Mans3eld Motors Manufacturers, *nc.4s lectrical Division, is leading a stud0 to assess the relative importance of product features. An item on a surve0 5uestionnaire distri6uted to 1!! of Mans3eld4s customers as"ed them to rate the importance of 7e?cienc0 of operation8 on a scale of 1 to 1! 9%ith 1 meaning 7not important8 and 1! meaning 7highl0 important8:. &is sta' assem6led the follo%ing statistics. ?cienc0 of peration Mean >.! ;tandard 2. De via tio n *f ugene concludes that the average rate of 7e?cienc0 of operation8 for all customers is >.!, he is using ________. M BApp
A. B. C. D.
D
Mar0 @lindt, a Mar"eting Director %ith psilon Airlines, is assessing the relative importance of the total ight eperience. An item on a surve0 5uestionnaire distri6uted to 1!! of psilons customers as"ed them to rate the importance of 7on/time arrival8 on a scale of 1 to 1! 9%ith 1 meaning 7not important8 and 1! meaning 7highl0 important8:. &er sta' assem6led the follo%ing statistics from the responses. n/time Arrival Mean E.1 ;tandard 2. De via tio n *f Mar0 concludes that the average rate of 7on/time arrival8 for all customers is E.1, she is using ________.
(.
M BApp
a point estimate a statistical parameter a range estimate an interval estimate
A. an interval estimate B. a statistical parameter C. a range estimate
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 2! D. a point estimate
2!> Test Ban" D <. Mar0 @lindt, a Mar"eting Director %ith psilon Airlines, is assessing the relative importance of the total ight eperience. An item on a surve0 5uestionnaire distri6uted to 1!! of psilons customers as"ed them to rate the importance of 7ca6in space8 on a scale of 1 to 1! 9%ith 1 meaning 7not important8 and 1! meaning 7highl0 important8:. &er sta' assem6led the follo%ing statistics from the responses. Ca6in ;pace Mean (.2 ;tandard #.( De via tio n *f Mar0 concludes that the average rate of 7ca6in space8 for all customers is (.2, she is using ________. M BApp
A. B. C. D.
B
The F value associated %ith a t%o/sided E!) con3dence interval is _______.
E.
an interval estimate a statistical parameter a range estimate a point estimate
Calc
A. B. C. D.
C
The F value associated %ith a t%o/sided E) con3dence interval is _______.
1!.
1.2< 1.>+ 1.E> 2.(
Calc
A. B. C. D.
B
The F value associated %ith a t%o/sided
11.
Calc
A. B. C. D.
1.2< 1.>+ 1.E> 2.(
1.>+ 1.2< !.<+ !.2E
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 2!(
2!< Test Ban" B 12. The F value associated %ith a t%o/sided <<) con3dence interval is _______. Calc
A. B. C. D.
D 1#.
The F value associated %ith a t%o/sided E2) con3dence interval is _______.
Calc
A. B. C. D.
B
The F value associated %ith a t%o/sided <2) con3dence interval is _______.
1+.
Calc
D 1.
A. B. C. D.
1.2< 1. 1.1( !.<<
1.+1 !.E2 !.+> 1.(
1.+1 1.#+ !.+> 1.(
;uppose a random sample of #> is selected from a population %ith a standard deviation of 12. *f the sample mean is E<, the EE) con3dence interval to estimate the population mean is _______.
M Calc
A. B. C. D.
A
;uppose a random sample of #> is selected from a population %ith a standard deviation of 12. *f the sample mean is E<, the E!) con3dence interval for the population mean is _______.
1>.
M Calc
A. B. C. D.
E+.!< to 1!1.E2 E2.< to 1!#.1 E(.# to E<.> E#.#+ to 1!2.>>
E+.(1 to 1!1.2E E(.+ to E<. E+.!< to 1!1.E2 E(.# to E<.>
C
1(.
M Calc
C
1<.
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 2!E ;uppose a random sample of #> is selected from a population %ith a standard deviation of 12. *f the sample mean is E<, the E) con3dence interval for the population mean is _______. A. B. C. D.
E+.(1 to 1!1.2E E(.+ to E<. E+.!< to 1!1.E2 E(.# to E<.>
;uppose a random sample of siGe >+ is selected from a population. The sample 0ields a mean of 2> and a standard deviation of +. @rom this information, the E!) con3dence interval to estimate the population mean can 6e computed to 6e _______.
M Calc
A. B. C. D.
B
Brian Vanecek, VP of Operations at Portland Trust Bank, is evaluating the service level provided to walk-in customers. Accordingly, his staff recorded the waiting times for 64 randomly selected walk-in customers, and determined that their mean waiting time was 15 minutes and that the standard deviation was 4 minutes. The 90% confidence interval for the population mean of waiting times is ________.
19.
2.#> to 2>.>+ 2.E2 to 2>.!< 2.1< to 2>.<2 2.E! to 2>.1!
M BCalc
A. B. C. D.
A
Brian Vanecek, VP of Operations at Portland Trust Bank, is evaluating the service level provided to walk-in customers. Accordingly, his staff recorded the waiting times for 64 randomly selected walk-in customers, and determined that their mean waiting time was 15 minutes and that the standard deviation was 4 minutes. The 95% confidence interval for the population mean of waiting times is ________.
20.
M BCalc
A. B. C. D.
14.27 to 15.73 1 4.06 to 15.94 9.88 to 20.12 13.86 to 16.14
13.88 to 16.12 7.16 to 22.84 14.06 to 15.94 8.42 to 21.58
21! D
Test Ban" 21.
Brian Vanecek, VP of Operations at Portland Trust Bank, is evaluating the service level provided to walk-in customers. Accordingly, his staff recorded the waiting times for 64 randomly selected walk-in customers, and determined that their mean waiting time was 15 minutes and that the standard deviation was 4 minutes. The 88% confidence interval for the population mean of waiting times is ________.
M BCalc
A. B. C. D.
B
Hames Desreumau, - of &uman $esources of American @irst Ban"s 9A@B:, is revie%ing the emplo0ee training programs of A@B 6an"s. &is sta' randoml0 selected personnel 3les for 1!! tellers in the ;outheast $egion , and determined that their mean training time was
22.
8.80 to 21.20 1 4.33 to 15.67 10.30 to 19.70 14.11 to 15.89
25 hours and that the standard deviation was 5 hours. The 88% confidence interval for the population mean of training times is ________. M BCalc
A. B. C. D.
17.25 to 32.75 2 4.23 to 25.78 24.42 to 25.59 19.15 to 30.85
D 2#.
Hames Desreumau, - of &uman $esources of American @irst Ban"s 9A@B:, is revie%ing the emplo0ee training programs of A@B 6an"s. &is sta' randoml0 selected personnel 3les for 1!! tellers in the ;outheast $egion , and determined that their mean training time was 25 hours and that the standard deviation was 5 hours. The 92% confidence interval for the population mean of training times is ________.
M BCalc
A. B. C. D.
16.25 to 33.75 2 4.30 to 25.71 17.95 to 32.05 24.13 to 25.99
C
2+.
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 211 Hames Desreumau, - of &uman $esources of American @irst Ban"s 9A@B:, is revie%ing the emplo0ee training programs of A@B 6an"s. &is sta' randoml0 selected personnel 3les for 1!! tellers in the ;outheast $egion , and determined that their mean training time was 25 hours and that the standard deviation was 5 hours. The 95% confidence interval for the population mean of training times is ________.
M BCalc
A. B. C. D.
B
ugene ates, Mar"eting Director of Mans3eld Motors Manufacturers, *nc.4s lectrical Division, is leading a stud0 to assess the relative importance of product features. An item on a surve0 5uestionnaire distri6uted to 121 of Mans3eld4s customers as"ed them to rate the importance of 7ease of maintenance8 on a scale of 1 to 1! 9%ith 1 meaning 7not important8 and 1! meaning 7highl0 important8:. &is sta' assem6led the follo%ing statistics. ase of Maintenance Mean (. ;tandard 1.1 De via tio n The 90% confidence interval for the population mean rating of 7ease of maintenance8 is ________.
2.
M BCalc
15.20 to 34.80 2 4.18 to 25.82 24.02 to 25.98 16.78 to 33.23
A. .#+ to E.>> B. (.#+ to (.>> C. .>E to E.#1 D. (.#! to (.(!
212 Test Ban" D 2>. ugene ates, Mar"eting Director of Mans3eld Motors Manufacturers, *nc.4s lectrical Division, is leading a stud0 to assess the relative importance of product features. An item on a surve0 5uestionnaire distri6uted to 121 of Mans3eld4s customers as"ed them to rate the importance of 7ease of maintenance8 on a scale of 1 to 1! 9%ith 1 meaning 7not important8 and 1! meaning 7highl0 important8:. &is sta' assem6led the follo%ing statistics. ase of Maintenance Mean (. ;tandard 1.1 De via tio n The 95% confidence interval for the population mean rating of 7ease of maintenance8 is ________. M BCalc
A. B. C. D.
A
Mar0 @lindt, a Mar"eting Director %ith psilon Airlines, is assessing the relative importance of the total ight eperience. An item on a surve0 5uestionnaire distri6uted to 1!! of psilons customers as"ed them to rate the importance of 7ca6in space8 on a scale of 1 to 1! 9%ith 1 meaning 7not important8 and 1! meaning 7highl0 important8:. &er sta' assem6led the follo%ing statistics from the responses. Ca6in ;pace Mean (.2 ;tandard #.( De via tio n The 95% confidence interval for the population mean rating of 7ca6in space8 is ________.
2(.
M BCalc
A. B. C. D.
.#+ to E.>> (.#+ to (.>> .>E to E.#1 (.#! to (.(!
>.+( to (.E# !.!! to 1+.+ !.!! to >.+( >.+( to 1+.+
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 21#
21+ Test Ban" C 2<. Mar0 @lindt, a Mar"eting Director %ith psilon Airlines, is assessing the relative importance of the total ight eperience. An item on a surve0 5uestionnaire distri6uted to 121 of psilons customers as"ed them to rate the importance of 7ca6in space8 on a scale of 1 to 1! 9%ith 1 meaning 7not important8 and 1! meaning 7highl0 important8:. &er sta' assem6led the follo%ing statistics from the responses. Ca6in ;pace Mean (.2 ;tandard #.( De via tio n The 99% confidence interval for the population mean rating of 7ca6in space8 is ________. M BCalc
A. B. C. D.
A
A random sample of >+ items is selected from a population of +!! items. The sample mean is 2!! and the sample standard deviation is +<. @rom this data, a E) con3dence interval to estimate the population mean can 6e computed as _______.
2E.
!.!! to (.#E !.!! to 1+.+ >.## to <.!( >.+( to 1+.+
M Calc
A. B. C. D.
1 1E!.1# to 2!E.<( 1E!.E+ to 2!E.!>
D #!.
A random sample of >+ items is selected from a population of +!! items. The sample mean is 2!! and the sample standard deviation is +<. @rom this data, a E!) con3dence interval to estimate the population mean can 6e computed as _______.
M Calc
A. B. C. D.
1 1E!.1# to 2!E.<( 1E!.E+ to 2!E.!>
A
#1.
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 21 A researcher %ants to estimate the proportion of the population %hich possess a given characteristic. A random sample of siGe >!! is ta"en resulting in ##! items %hich possess the characteristic. The point estimate for this population proportion is _______.
Calc
A. B. C. D.
C
The normal distri6ution is used to test a6out a population mean for large samples. Iarge is usuall0 de3ned as _______.
#2.
Term
B
##.
Term
C
#+.
M Term
B
#.
M Term
A. B. C. D.
!. !.## !.>! !.+
at least 1!! at least ) of the population siGe at least #! at least 12
The t test %as developed 60 _______. A. B. C. D.
Charles ;tudent William osset deMoivre auss
The t/distri6ution is similar to a normal distri6ution. &o%ever the t/distri6ution is _______. A. B. C. D.
not s0mmetric 6imodal atter discrete
The t/distri6ution is similar to a normal distri6ution. &o%ever the t/distri6ution is a _______. A. B. C. D.
lepto"urtic distri6ution plat0"urtic distri6ution mesopotamian distri6ution discrete distri6ution
21> Test Ban" B #>. *n order to 3nd values in the t distri6ution ta6le, 0ou must convert the sample siGe or siGes to _______. Term
A
#(.
M Term
B
#<.
A. B. C. D.
population siGes degrees of freedom F values student values
*f the degrees of freedom in a t distri6ution get ver0 large, _______. A. B. C. D.
the t values and the F values are almost the same the sample siGe must 6e ver0 small the population siGe must 6e ver0 large the sample mean approaches Gero
The ta6le t value associated %ith the upper ) of the t distri6ution and 12 degrees of freedom is _______.
Calc
A. B. C. D.
D #E.
The ta6le t value associated %ith the upper ) of the t distri6ution and 1+ degrees of freedom is _______.
Calc
A. B. C. D.
A
The ta6le t value associated %ith the upper 1!) of the t distri6ution and 2# degrees of freedom is _______.
+!.
Calc
A. B. C. D.
2.1(E 1.(<2 1.#> #.!
2.E(( 2.>2+ 2.1+ 1.(>1
1.#1E 1.(1+ 2.!>E 1.#21
B
+1.
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 21( The ta6le t value associated %ith the upper 1) of the t distri6ution and degrees of freedom is _______.
Calc
A. B. C. D.
A
The ta6le t value associated %ith the upper 1!) of the t distri6ution and 1( degrees of freedom is _______.
+2.
+.!#2 #.#> #.(+( 1.+(>
Calc
A. B. C. D.
D +#.
The ta6le t value associated %ith the upper ) of the t distri6ution and 1 degrees of freedom is _______.
Calc
A. B. C. D.
A
The ta6le t value associated %ith the upper !.) of the t distri6ution and + degrees of freedom is _______.
++.
1.### 1.##( 1.(+! 2.>(
2.E+( 2.>!2 2.1#1 1.(#
Calc
A. B. C. D.
B
The ta6le t value associated %ith 1! degrees of freedom and used to compute a E) con3dence interval is _______.
+.
Calc
A. B. C. D.
+.>!+ 2.((> 2.1#2 2.##
1.<12 2.22< #.1>E 1.#(2
21< Test Ban" B +>. The ta6le t value associated %ith 12 degrees of freedom and used to compute a E) con3dence interval is _______. Calc
A. B. C. D.
B
The ta6le t value associated %ith 21 degrees of freedom and used to compute a E!) con3dence interval is _______.
+(.
#.! 2.1(E 1.(<2 1.(E>
Calc
A. B. C. D.
C
The ta6le t value associated %ith < degrees of freedom and used to compute a EE) con3dence interval is _______.
+<.
1.#2# 1.(21 2.!
Calc
A. B. C. D.
C
A researcher is interested in estimating the mean value for a population. ;he ta"es a random sample of 1( items and computes a sample mean of 22+ and a sample standard deviation of #2. ;he decides to construct a E<) con3dence interval to estimate the mean. The degrees of freedom associated %ith this pro6lem are _______.
+E.
Calc
A. B. C. D.
1.#E( 1.<>! #.# 2.
1< 1( 1> 1
C
!.
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 21E The lengths of steel rods produced 60 a shearing process are normall0 distri6uted. A random sample of 1! rods is selectedJ the sample mean length is 11E.! inchesJ and the sample standard deviation is !.1! inch. The 95% confidence interval for the population mean rod length is ______________.
M BCalc
A. B. C. D.
A
The lengths of steel rods produced 60 a shearing process are normall0 distri6uted. A random sample of 1! rods is selectedJ the sample mean length is 11E.! inchesJ and the sample standard deviation is !.1! inch. The 90% confidence interval for the population mean rod length is ______________.
1.
11<.EE to 11E.11 11<.<2 to 11E.2< 11<.E< to 11E.12 11<.< to 11E.2
M BCalc
A. B. C. D.
B
The %eights of aluminum castings produced 60 a process are normall0 distri6uted. A random sample of castings is selectedJ the sample mean %eight is 2.21 poundsJ and the sample standard deviation is !.12 pound. The 98% confidence interval for the population mean casting weight is _________.
2.
11<.EE to 11E.11 11<.<( to 11E.2# 11E.!! to 11E.1! 11<.
M BCalc
A. B. C. D.
1.(> to 2.>> 2.!1 to 2.+1 2.!< to 2.#+ 1.E# to 2.+E
D #.
Iife tests performed on a sample of 1# 6atteries of a ne% model indicated= 91: an average life of ( months, and 92: a standard deviation of months. ther 6atter0 models, produced 60 similar processes, have normall0 distri6uted life spans. The 98% confidence interval for the population mean life of the new model is _________.
M BCalc
A. B. C. D.
>#.#( to <>.># >1.>! to <<.+1 (1.(( to (<.2# (1.2< to (<.(2
22! Test Ban" C +. Iife tests performed on a sample of 1# 6atteries of a ne% model indicated= 91: an average life of ( months, and 92: a standard deviation of months. ther 6atter0 models, produced 60 similar processes, have normall0 distri6uted life spans. The 90% confidence interval for the population mean life of the new model is _________. M BCalc
A. B. C. D.
B
A researcher %ants to estimate the proportion of the population %hich possess a given characteristic. A random sample of siGe ! items %hich possess the characteristic. The point estimate for this population proportion is _______.
.
Calc
A
>.
M Calc
B
(.
M Calc
A. B. C. D.
>>.(< to <#.2# (2.(2 to ((.2< (2.# to ((.+( >>.!E to <#.E1
!. !.+ !.# !.>
A researcher %ants to estimate the proportion of a population %hich possess a given characteristic. A random sample of siGe 2! is ta"en and +!) of the sample possess the characteristic. The E!) con3dence interval to estimate the population proportion is _______. A. B. C. D.
!.# to !.+ !.#+ to !.+> !.#( to !.+# !.#E to !.+1
A researcher %ants to estimate the proportion of a population %hich possess a given characteristic. A random sample of siGe 2! is ta"en and +!) of the sample possess the characteristic. The E) con3dence interval to estimate the population proportion is _______. A. B. C. D.
!.# to !.+ !.#+ to !.+> !.#( to !.+# !.#E to !.+1
C
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 221 <. A researcher %ants to estimate the proportion of a population %hich possess a given characteristic. A random sample of siGe 2!! is ta"en and #!) of the sample possess the characteristic. The E) con3dence interval to estimate the population proportion is _______.
M Calc
B
E.
M Calc
D >!.
M Calc
A
>1.
M Calc
A. B. C. D.
!.# to !.>( !.2 to !.# !.2+ to !.#> !.2( to !.##
A researcher %ants to estimate the proportion of a population %hich possess a given characteristic. A random sample of siGe 2!! is ta"en and #!) of the sample possess the characteristic. The E!) con3dence interval to estimate the population proportion is _______. A. B. C. D.
!.# to !.>( !.2 to !.# !.2+ to !.#> !.2( to !.##
A random sample of 22 items from a population results in >!) possessing a given characteristic. Ksing this information, the researcher constructs a EE) con3dence interval to estimate the population proportion. The resulting con3dence interval is _______. A. B. C. D.
!.+ to !.>> !.E to !.>1 !.( to !.># !.2 to !.><
A random sample of 22 items from a population results in >!) possessing a given characteristic. Ksing this information, the researcher constructs a E!) con3dence interval to estimate the population proportion. The resulting con3dence interval is _______. A. B. C. D.
!.+> to !.>+ !.#> to !.>>+ !.E> to !.>!+ !.(1 to !.>2E
222 Test Ban" A >2. l%in s6ourne, C* at @;, *nc., is stud0ing emplo0ee use of @; e/mail for non/6usiness communications. A random sample of 2!! e/mail messages %as selected. Thirt0 of the messages %ere not 6usiness related. The point estimate for this population proportion is _______. BApp
A. 0.150 B. !.#!! C. !.1<2 D. !.>>(
A
l%in s6ourne, C* at @;, *nc., is stud0ing emplo0ee use of @; e/mail for non/6usiness communications. A random sample of 2!! e/mail messages %as selected. Thirt0 of the messages %ere not 6usiness related. The 90% confidence interval for the population proportion is _________.
>#.
M BCalc
A. B. C. D.
D >+.
l%in s6ourne, C* at @;, *nc., is stud0ing emplo0ee use of @; e/mail for non/6usiness communications. A random sample of 2!! e/mail messages %as selected. Thirt0 of the messages %ere not 6usiness related. The 95% confidence interval for the population proportion is _________.
M BCalc
A. B. C. D.
C
l%in s6ourne, C* at @;, *nc., is stud0ing emplo0ee use of @; e/mail for non/6usiness communications. A random sample of 2!! e/mail messages %as selected. Thirt0 of the messages %ere not 6usiness related. The 98% confidence interval for the population proportion is _________.
>.
M BCalc
A. B. C. D.
!.1!< to !.1E2 !.1# to !.2+( !.!E1 to !.2!E !.1+ to !.2
!.1!< to !.1E2 !.1# to !.2+( !.!E1 to !.2!E !.1!1 to !.1EE
!.1!< to !.1E2 !.1# to !.2+( !.!E1 to !.2!E !.1+ to !.2
A
>>.
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 22# Catherine Chao, Director of Mar"eting $esearch, is evaluating consumer acceptance of a ne% toothpaste pac"age. ;he randoml0 selects a sample of 2!! households. @ort0 households prefer the ne% pac"age to all other pac"age designs. The point estimate for this population proportion is _______.
M BCalc
A. B. C. D.
B
Catherine Chao, Director of Mar"eting $esearch, is evaluating consumer acceptance of a ne% toothpaste pac"age. ;he randoml0 selects a sample of 2!! households. @ort0 households prefer the ne% pac"age to all other pac"age designs. The 90% confidence interval for the population proportion is _________.
>(.
!.2! !.2 !.+! !.+
M BCalc
A. B. C. D.
C
Catherine Chao, Director of Mar"eting $esearch, is evaluating consumer acceptance of a ne% toothpaste pac"age. ;he randoml0 selects a sample of 2!! households. @ort0 households prefer the ne% pac"age to all other pac"age designs. The 95% confidence interval for the population proportion is _________.
><.
M BCalc
C
>E.
M BCalc
A. B. C. D.
!.1EE to !.2!1 !.1# to !.2+( !.1>+ to !.2#> !.1+ to !.2
!.1# to !.2+( !.1EE to !2.!1 !.1+ to !.2 !.1E< to !.2!2
phelia Brien, - of Consumer Credit of American @irst Ban"s 9A@B:, has implemented a fast feed6ac" to "eep her informed of the default rate on personal loans at the A@B mem6er 6an"s. n each @rida0, the default rate is calculated for a sample of !! personal loans. Iast @rida0s sample contained #! defaulted loans. The point estimate for this population proportion is _______. A. !.!!!2 B. 1>.>(! C. !.!>!!
22+
Test Ban" D. !.!###
A
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 22 (!. phelia Brien, - of Consumer Credit of American @irst Ban"s 9A@B:, has implemented a fast feed6ac" to "eep her informed of the default rate on personal loans at the A@B mem6er 6an"s. n each @rida0, the default rate is calculated for a sample of !! personal loans. Iast @rida0s sample contained #! defaulted loans. The 90% confidence interval for the population proportion is _________.
M BCalc
D (1.
A. B. C. D.
!.!+# to !.!(( !.!+> to !.!(+ !.!#E to !.!<1 !.!2< to !.!>!
phelia Brien, - of Consumer Credit of American @irst Ban"s 9A@B:, has implemented a fast feed6ac" to "eep her informed of the default rate on personal loans at the A@B mem6er 6an"s. n each @rida0, the default rate is calculated for a sample of !! personal loans. Iast @rida0s sample contained #! defaulted loans. The 95% confidence interval for the population proportion is _________.
M BCalc
A. B. C. D.
A
Brian Vanecek, VP of Operations at Portland Trust Bank, is evaluating the service level provided to walk-in customers. Brian would like to minimize the variance of waiting time for these customers, since this would mean each customer received the same level of service. Accordingly, his staff recorded the waiting times for 15 randomly selected walk-in customers, and determined that their mean waiting time was 15 minutes and that the variance was 4 minutes. The 90% confidence interval for the population variance of waiting times is ________.
72.
M BCalc
A. B. C. D.
!.!+# to !.!(( !.!+> to !.!(+ !.!2< to !.!>! !.!#E to !.!<1
9.46 to 34.09 5 6.25 to 64.87 11.05 to 16.03 8.58 to 39.79
22> D
Test Ban" 73.
Brian Vanecek, VP of Operations at Portland Trust Bank, is evaluating the service level provided to walk-in customers. Brian would like to minimize the variance of waiting time for these customers, since this would mean each customer received the same level of service. Accordingly, his staff recorded the waiting times for 15 randomly selected walk-in customers, and determined that their mean waiting time was 15 minutes and that the variance was 4 minutes. The 95% confidence interval for the population variance of waiting times is ________.
M BCalc
A. B. C. D.
C
elma as5ueG, fund manager of the as5ueG alue @und, manages a portfolio of 2! common stoc"s. elma relies on various statistics, such as variance, to assess the overall ris" of stoc"s in an economic sector. &er sta' reported that for a sample 1+ utilit0 stoc"s the mean annualiGed return %as 1+) and that the variance %as #). The 90% confidence interval for the
(+.
9.46 to 34.09 5 6.25 to 64.87 11.05 to 16.03 8.58 to 39.79
population variance of annualized returns is _______. M BCalc
A. B. C. D.
B
elma as5ueG, fund manager of the as5ueG alue @und, manages a portfolio of 2! common stoc"s. elma relies on various statistics, such as variance, to assess the overall ris" of stoc"s in an economic sector. &er sta' reported that for a sample 1+ utilit0 stoc"s the mean annualiGed return %as 1+) and that the variance %as #). The 95% confidence interval for the
(.
0.018 to 0.064 0 .016 to 0.078 0.017 to 0.066 0.016 to 0.075
population variance of annualized returns is _______. M BCalc
A. B. C. D.
0.018 to 0.064 0 .016 to 0.078 0.017 to 0.066 0.016 to 0.075
D (>.
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 22( Hames Desreumau, - of &uman $esources of American @irst Ban"s 9A@B:, is revie%ing the emplo0ee training programs of A@B 6an"s. &is sta' randoml0 selected personnel 3les for 1! tellers in the ;outh%est $egion , and determined that their mean training time was 25 hours and that the standard deviation was 5 hours. The 90% confidence interval for the population variance of training times is ________.
M BCalc
A. B. C. D.
A
Hames Desreumau, - of &uman $esources of American @irst Ban"s 9A@B:, is revie%ing the emplo0ee training programs of A@B 6an"s. &is sta' randoml0 selected personnel 3les for 1! tellers in the ;outh%est $egion , and determined that their mean training time was
((.
11.83 to 83.33 2.37 to 16.67 2.66 to 13.51 13.30 to 67.57
25 hours and that the standard deviation was 5 hours. The 95% confidence interval for the population variance of training times is ________. M BCalc
B
(<.
M Term
B
(E.
Term
A. B. C. D.
11.83 to 83.33 2.37 to 16.67 2.66 to 13.51 13.30 to 67.57
The 3nite correction factor should 6e used if the sample siGe is _______. A. B. C. D.
less than ) of the population siGe more than ) of the population siGe less than #! more than 1!!
*n 3nding a con3dence interval for the population mean, the population standard deviation should 6e used if it is "no%n. *f the population standard deviation is not "no%n, then it should 6e estimated %ith _______. A. B. C. D.
the sample variance the sample standard deviation the range the mean
22< Test Ban" A
A. B. C. D.
A
*n estimating the sample siGe necessar0 to estimate a population mean, the error of estimation, , is e5ual to _______.
<1.
Term
B
<2.
M Term
C
<#.
M Calc
!.+!1 to !.+#E !.+!E to !.+#1 !.#E2 to !.++< !.#
A. the distance 6et%een the sample mean and the population mean B. the distance 6et%een the sample mean and the variance C. the F score D. the sample siGe *n estimating sample siGe, if the population standard deviation is un"no%n, it can 6e estimated 60 using _______. A. B. C. D.
the population mean one/fourth of the range one/half of the range the F score
;uppose a researcher %ants to conduct a stud0 to estimate the population mean. &e plans to use a E) level of con3dence to estimate the mean, and the population standard deviation is approimatel0 #+. The researcher %ants the error to 6e no more than +. The sample siGe should 6e at least _______. A. B. C. D.
( 1E> 2(< 111!
B
<+.
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 22E Hames Desreumau, - of &uman $esources of American @irst Ban"s 9A@B:, is revie%ing the emplo0ee training programs of A@B 6an"s. &e plans to use a E) con3dence interval estimate of mean training time of tellers and is willing to accept an error of 1 hour; previous studies indicated a standard deviation of 2 hours. The sample siGe should
6e at least _______. M BCalc
A. B. C. D.
B
Hames Desreumau, - of &uman $esources of American @irst Ban"s 9A@B:, is revie%ing the emplo0ee training programs of A@B 6an"s. &e plans to use a E!) con3dence interval estimate of
<.
4 16 34 68
mean training time of tellers and is willing to accept an error of 1 hour; previous studies indicated a standard deviation of 5 hours. The sample siGe should
6e at least _______. M BCalc
A. B. C. D.
A
A researcher %ants to determine the sample siGe necessar0 to ade5uatel0 conduct a stud0 to estimate the population mean to %ithin points. The range of population values is
<>.
4 16 34 68
M Calc
A. B. C. D.
C
A stud0 is going to 6e conducted in %hich a population mean %ill 6e estimated using a E2) con3dence interval. The estimate needs to 6e %ithin 12 of the actual population mean. The population variance is estimated to 6e around 2!!. The necessar0 sample siGe should 6e at least _______.
<(.
M Calc
++ >2 21> >E2
A. 1 B. +( C. #
2#! B
Test Ban" D. >#< <<.
Term
*n estimating the sample siGe necessar0 to estimate -, if there is no good approimation for the value of - availa6le, the value of ____ should 6e used as an estimate of - in the formula. A. B. C. D.
!.1! !.! !.+! 1.E>
D
A researcher %ants to estimate the population proportion %ith a E) level of con3dence. &e estimates from previous studies that the population proportion is no more than .#!. The researcher %ants the estimate to have an error of no more than . !#. The necessar0 sample siGe is at least _______.
M Calc
A. B. C. D.
C
Catherine Chao, Director of Mar"eting $esearch, is evaluating consumer acceptance of a ne% toothpaste pac"age. ;he plans to use a E) con3dence interval estimate of the proportion of households %hich prefer the ne% pac"agesJ she %ill accept a !.! error. -revious studies indicate that ne% pac"aging has an approimatel0 (!) acceptance rate. The sample siGe should 6e at least _______.
E!.
2( 1<< 211
M BCalc
A. B. C. D.
B
Catherine Chao, Director of Mar"eting $esearch, is evaluating consumer acceptance of a ne% toothpaste pac"age. ;he plans to use a
E1.
M BCalc
2( E #2# +2(
A. 2( B. E
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 2#1 C. #2# D. +2(
2#2 Test Ban" A E2. l%in s6ourne, C* at @;, *nc., is stud0ing emplo0ee use of @; e/mail for non/6usiness communications. &e plans to use a E) con3dence interval estimate of the proportion of e/mail messages that are non/6usinessJ he %ill accept a !.! error. -revious studies indicate that approimatel0 #!) of emplo0ee e/ mail is not 6usiness related. l%in should sample _______ e/mail messages. BApp
A. 323 B. 12 C. +( D. 1+
C
l%in s6ourne, C* at @;, *nc., is stud0ing emplo0ee use of @; e/mail for non/6usiness communications. &e plans to use a E<) con3dence interval estimate of the proportion of e/mail messages that are non/6usinessJ he %ill accept a !.! error. -revious studies indicate that approimatel0 #!) of emplo0ee e/ mail is not 6usiness related. l%in should sample _______ e/mail messages.
E#.
BApp
A. 323 B. 12 C. +( D. 1+
D E+.
A researcher %ants to estimate the population proportion %ith a E!) level of con3dence. ;he estimates from previous studies that the population proportion is no more than .#!. The researcher %ants the estimate to have an error of no more than . !2. The necessar0 sample siGe is at least _______.
M Calc
A. B. C. D.
A
A stud0 %ill 6e conducted to estimate the population proportion. A level of con3dence of EE) %ill 6e used and an error of no more than .!+ is desired. There is no "no%ledge as to %hat the population proportion %ill 6e. The siGe of sample should 6e at least _______.
E.
M Calc
2E +( 2E< 1+21
A. 1!#> B. 1>!
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 2## C. +1 D. 2E D E>.
A researcher conducts a stud0 to determine %hat the population proportion is for a given characteristic. *t is 6elieved from previous studies that the proportion of the population %ill 6e at least .>. The researcher %ants to use a E<) level of con3dence. &e also %ants the error to 6e no more than .!#. The sample siGe should 6e at least _______.
M Calc
A. B. C. D.
B
ou %ish to determine the proportion of all secretaries %ho are familiar %ith a particular %ord processing pac"age. ou %ill conduct a random surve0. &o% large a sample should 0ou ta"e if 0ou %ant to 6e E) con3dent of the results and %ithin !.! of the true population proportionL
E(.
+1 #1# 1>(( 1#(#
M Calc
A. B. C. D.
C
ou %ish to determine the proportion of all secretaries %ho are familiar %ith a particular %ord processing pac"age. ou %ill conduct a random surve0. &o% large a sample should 0ou ta"e if 0ou %ant to 6e E!) con3dent of the results and %ithin !.!+ of the true population proportionL
E<.
(# #<+ E 2((
M Calc
A. B. C. D.
B
A 6an" o?cer %ishes to estimate the amount of the average total deposits per customer at the 6an". ;he %ishes the estimate to 6e %ithin N2!! of the actual average %ith E) con3dence. ;he assumes the standard deviation for this should 6e N1!!!. &o% large should the sample 6eL
M
EE.
12 21> +2# >!!
A. 1!
2#+ Test Ban" BCalc B. E> C. >< D. 1E,2!<
B 1!!.
M BCalc
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 2# A 6an" o?cer %ishes to estimate the amount of the average total deposits per customer at the 6an". ;he %ishes the estimate to 6e %ithin N1!! of the actual average %ith E!) con3dence. ;he assumes the standard deviation for this should 6e N
1 1(# 2+> 1(,#1<
2#>
Test Ban" 101.
While evaluating the service level provided to walk-in customers, Brian Vanecek, VP of Operations at Portland Trust Bank, encountered resistance to some of his proposals from fellow executives. Brian focuses on providing timely, efficient service to the banks customers; customers having to wait for service upsets him; and some customers share his philosophy, but not all. The VP of Marketing points out that some customers (for various reasons) "don't want to rush in and out." Moreover, the bank's management wants to provide a warm friendly atmosphere for customers. Identify some potential segments of the bank's walk-in customers. (Are drivethrough customers a distinct segment?) How can a statistical analysis of walk-in customers help identify and evaluate service alternatives for the segments? What estimates are needed?
M BApp
_________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________
1!2.
Chapter <= ;tatistical *nference= stimation for ;ingle -opulations 2#( ;toc"ton ;teel, *nc. can 5ualif0 for a lucrative contract to suppl0 steel rods if it can meet the 6u0er4s process capa6ilit0 re5uirements. ;peci3call0, the 6u0er re5uires documented evidence that the standard deviation of ;toc"tons process is no more than 1O12th of the di'erence 6et%een the upper tolerance limit and the lo%er tolerance limit, σ ≤ 9KTI / ITI:O12. ;arah ;hum, Director of Pualit0 -rograms, is assigned the tas" of developing the documentation. ;he "no%s that varia6ilit0 of the rod length depends on several factors= the operators s"ill, the mi used in the steel melt, the 5ualit0 of materials used in the mi, and the condition of the e5uipment.
M BApp
Discuss ;arahs assignment. What estimates does she needL Which departments must participate in the process capa6ilit0 stud0L Which of these departments %ill not participate after completion of the stud0L _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________
2#<
Test Ban" 1!#. Alan Iesso', - of Mar"eting at C06erWarehouse, *nc. 9CW*:, %ants to learn more a6out online shoppers that visit the C0perWarehouse %e6 sites. Identify some potential segments of the CWI's online shoppers. (Are repeatvisitors a distinct segment?) How can a statistical analysis of online shoppers help identify and evaluate service alternatives, merchandise selection, and web site design for the segments? What estimates are needed?
M BApp
