FACULTY OF APPLIED SCIENCE BACHELOR OF SCIENCE (HONS) BIOLOGY BIOLOGY DEPARTMENT BIO510 ASB2Cb EXPERIMENT 1: BASIC CONCEPTS OF STATISTICS AND VARIATION
STUDENT'S NAME STUDENT'S NAME STUDENT'S NAME
MOHAMAD SYAMIL BIN MD. JANI MUHAMMAD AIZUDDIN BIN KHALID MOHD NAWAF BIN MOHD YUSOFF
2013618492 2013689746 2013840534
LECTURER'S NAME: Dr. HASNUN NITA BINTI ISMAIL DATE OF EXPERIMENT: 10 MARCH 2014 DATE OF SUBMIT: 14 MARCH 2014
OBJECTIVE
To calculate the following descriptive statistic: mean, variance and
standard deviation To introduce the concept of normal distribution To determine the relationship between the two variables To develop understanding and apply the basic concept of statistic and variation in population
METHOD
A set containing 10 pieces of leaves was picked, measured and recorded their length and width. Based on the data collected, the mean, variance and standard deviation of the length and width were
calculated. The mean weight of the 10 leaves was also measured. The process was repeated with another 5 set of leaves. The data gained from the 50 leaves was used to plot a graph of leave length versus leave width.
Result
Mean Length VS Mean Width 6.2
6
5.8
f(x) = 0.26x + 0.58 R² = 0.88
5.6 mean length
Linear () 5.4
5.2
5
4.8 17
17.5
18
18.5
19
mean width
19.5
20
20.5
Leaves lenght vs Leaves Width 12
10
8
leaves lenght
6
f(x) = 0.08x + 4.12 R² = 0.03
Linear ()
4
2
0 5
10
15
20
leaves width
25
30
DISCUSSION The experiment was done to study the relationship between length and width of the leaves. This experiment also was carry out to determine and applying the basic concept of statistic and variation in population. 50 pieces of leaves of random length and width was divided into a set of tens and later measured its length, width and weight. The data was collected and a graph of length versus width was plotted. The statistical value such as mean, variance and standard deviation was also calculated. The graph has been plotted shown that the width of leaves increase directly proportional with its length. Although the data shown that the line was not completely accurate, the distribution of the data shows it scatters into a form of linear increase. So, the length and width can be conclude as dependence, where the longer the length of the leaves, the wider the width of the leaves. The statistical values of the experiment; mean, variance and standard deviation also play a vital part in proposing this conclusion. Mean can be defined as the sum of all the value divided with the number of the value. Mean can be used as the central tendency to observe the data distribution meanwhile, variance is used to measure how far the data spread out from the mean value. The smaller the variance value, the smaller it spread out from the mean value. Based on the calculation, the variance from the experiment has a small value, showing that our data doesn’t spread away too much from its mean. The data distribute nicely along the linear line, showing the dependence of the two variables. The same case applies to the standard deviation. Standard deviation also measure how much the data distribute from the mean value. The smaller the value of the standard deviation, the smaller the value of data spread from the mean. Based on the evidence above, we can conclude that the higher the length, the higher the width. The variables depend on each other.
CONCLUSION As the conclusion we have learned in how to calculate and determine the mean, variance and standard variation. From the experiment, we can conclude that the higher the length, the higher the width. depend on each other.
REFERENCE
UiTM BIO 510 Laboratory Manual http://www.mathsisfun.com/data/standard-deviation.html http://www.mathsisfun.com/mean.html
The variables
POST-LAB QUESTIONS 1. What can you say about the mean length and mean width of the different sets of the leaves. Are they very different or similar? How did you arrive at this conclusion? Discuss. There are difference in the mean length and mean width in the different sets of the leaves. However, there is no drastic difference in those sets. The difference is maybe because the age of the individual leaves. The leaves are from the same species, based on their similar appearances. The size of the leaf grows with its age. Therefore, the younger the leaf, the smaller its size. The leaves are randomly divided into 5 sets of tens. However, it was arranged into a similar size, causing the mean value was not differ much from the individual value.
2.
What
is
meant
by
variance?
“The
leaves
have
different
measurement of the width and length”. What is the meaning of this statement? Discuss with respect to variance. What is meant by the “standard deviation”? Variance is used to measure how much the data spread out from the mean value. The statement shows that there are variation in length and width of a group of leaves. There is no similar individual in a population whether in
appearance or size. However, the size doesn’t differ drastically with each other as proved by the variance. The calculated variance has a small value, showing that the length and width of the leaves didn’t spread away too much from its mean value. This is because the smaller the value of variance, the smaller the spread of data distribution from the mean value. Standard deviation also used to measure the dispersion of data from its mean value. Standard deviation is easier to use in real-life problem as it is the square root of variance thus has similar unit as the data e.g if data in cm, variance will be in cm2 while standard deviation will be same as the data, which is cm.
3. What could be the possible errors during the data recording? There are not many possible errors that could happen during this experiment because the procedure was quite simple and straight forward. However, it is not an excuse not be careful during conducting this experiment. The first possible error that might occur is during the recording the data. The leaves are from the same species, based on similar appearance, therefore confusion while taking the measurement could happen. The correct way to avoid the error is by measuring one leaf at a time, taking both its length and width first before proceeding to the next one. Labeling the leaf’s number also will help avoiding the error.
The next possible error also might happen during the
process of recording the data. Student must determine the correct point to start taking measurement for length and width. If the point was not determined properly before taking the measurement, the data might not be correct and uniform. All possible error must be eliminated to get an accurate and consistent result.
4. Why is it necessary to have different set of measurement for the leaves width and length? It is necessary to have different set of measurement for leaves width and length because to ensure a consistent result. It is hard to determine whether the results are correct if only one set was used. By having different sets, we can compare our result with the other set for consistent result. It also obeys the law of nature because there is no similar individual in a population.
