LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION – STATISTICS
SUPPLEMENTARY EXAMINATION – JUNE 2008
ST 3901 - STATISTICAL APPLICATIONS IN BIOLOGICAL SCIENCES
Date : 28-06-08
Time : 9:00 - 12:00
Dept. No.
Max. : 100 Marks
PART A
Answer all the questions.
5 X 2 = 10
1. Write any two sources from which Primary data are obtained.
2. Define biostatistics.
3. Distinguish between Parameter and Statistic
4. State any two applications of Statistics in Bio-Medical science studies.
5. What measures are available in measure of central tendency?
6. State any two properties of correlation.
7. Declare any four characteristics of Normal distribution.
8. Define Skewness.
9. What are the advantages of Sampling?
10. Mention any two uses of ANOVA while conducting Biological experiments.
PART B
Answer any FIVE questions.
5 X 8 = 40
11. Distinguish between Diagrammatic representation and graphical representation of data. Illustrate
any four Diagrammatic representations of data.
12. Compute mean and median for the following data:
Age
: 20-30 30-40 40-50 50-60 60-70 70-80 80-90
Number of patients : 15
19
11
25
22
10
5
13. Calculate correlation coefficient for weights (kg) and heights (cm) of 10 patients in Maruthi
hospital.
Weight : 83 99
63
71
65
70
69
56
66
88
Height : 185 180
173
168
175
183
174
164
169
205
14. Explain various steps in involved in Hypothesis testing.
15. The Weights (in Kg.) of 8 Obese Women before and after 12-weeks of VLCD(very low calorie
diet) treatment are given in following table. Test whether these data provide sufficient evidence to
allow us to conclude that the treatment is effective in causing weight reduction in obese women?
Let =0.05
Before : 104
After
: 89
96
78
103 105 100 87 85 72
89
83
77
67 60 69
1
16. The following data are the oxygen uptakes (milliliters) during incubation of a random sample of
15 cell suspensions.
14.0 14.1 14.5 13.2 11.2 14.0 14.1 12.2 11.1 13.7 13.2
16.0 12.8 14.4 12.9
Do these data provide sufficient evidence at the 0.05 level of significance that the population
mean is not 12ml?
17. In a random sample of 600 and 1000 men from two cities, 400 and 600 men are found to be
illiterate. Do the data indicate at 5%level of significance that the population is significantly
different in the percentage of literacy?
18. A rifle club performed an experiment on a randomly selected group of first-time shooters. The
purpose of the experiment was to determine whether shooting accuracy is affected by the method
of sighting used: only the right eye open, only the left eye open, or both eyes open. Fifteen firsttime shooters were selected and divided into three groups. Each group experienced the same
training and practicing procedures with one exception: the method of sighting used. After
completing training, each student was given the same number of rounds and asked to shoot at a
target. Their scores are listed in the given table.
Method of shooting
Left eye
Both eyes
Right eye
12
10
18
12
14
10
17
16
13
16
14
16
11
20
21
At the 0.05 level of significance, is there sufficient evidence to reject the claim that the three
methods of sighting are equally effective?
SECTION C
Answer any TWO questions
(2 x 20 =40)
19. In a research study, Drug dose in mg and heart-rate reduction values were observed from 10
patients.
Drug dose in mg
0.5 0.75 1.00 1.25 1.50 1.75 2 2.25 2.50 2.75
Heart-rate reduction
10
7
15
12
15
14
20
20
18
21
a) Construct Regression equations and hence estimate the heart-rate reduction when drug dose is
095 mg
b) Compute r2 and give your interpretation.
20. a) The following table gives heights of boys and girls studying in a college. Calculate coefficient
of variation for boys and girls and verify whose heights are more consistent?
Boys
Girls
Number
400
100
Average Height
68 inches
65 inches
Variance
9
4
2
b) A study was designed to estimate the difference in diastolic blood pressures between men and
women.
Men: 76
76
74
70
80
68
90
70
76
80
Women:82
90
68
60
62
60
62
72
68
74
Verify men and women are equal in diastolic blood pressures by using two sample independent ttest at 5 % level of significance.
21. a) Two hundred adults who professed to love hot, spicy food were asked to name their favorite
way to cool their mouth after eating food with hot sauce. Here is the summary of the sample:
Method Water Milk Soda Beer Bread Others Nothing
Number 73
35
20
19
29
11
13
Use chi-square test to test whether rinsing methods are equally effective and give your
interpretation at 5 % level of significance.
b) In a hospital 480 female and 520 male babies were born in a week. Do these figures
confirm the hospital that the male and female babies are born in equal number?
22. A re-motivation team in a psychiatric hospital conducted an experiment to compare five methods
for re-motivating patients. Patients were grouped according to level of initial motivation. Patients
in each group were randomly assigned to the five methods. At the end of the experimental period
the patients were evaluated by a team composed of a psychiatrist, a psychologist, a nurse and a
social worker, none of whom was aware of the method to which patients had been assigned. The
team assigned each patient a composite score as a measure of his/her level of motivation. The
results were as follows:
Level of Initial
Re-motivation method
motivation
A
B
C
D
Nil
58
68
60
68
Very Low
62
70
65
80
Low
67
78
68
81
Average
70
81
70
89
Perform 2-way ANOVA and interpret your results.
E
64
69
70
74
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