LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

AC 45

M.Sc. DEGREE EXAMINATION – BMIS

THIRD SEMESTER – APRIL 2007

ST 3901 – STATISTICAL APPLICATION IN BIOLOGICAL SC.

Date & Time: 02/05/2007 / 9:00 – 12:00 Dept. No. Max. : 100 Marks

SECTION A

Answer ALL questions. Each carries 2 marks [10×2=20]

State any two applications of Statistics in Biological
Define Secondary data and write any two sources of getting Health related data.
Distinguish between Bar diagram and Histogram by a suitable example from Biological sciences.
Write any two Biological scenario for which the ‘Scatter diagram’ is applied.
Explain any two advantages of Co-efficient of Variation over measures of Dispersion.
Define a] Sample space b] Random variable.
What do you understand from the term ‘Standard Error’ ?
Distinguish between Parameter and
Illustrate the application of t-distribution in Biological studies.
What is meant by ‘Analysis Of Variance’(ANOVA)? State its uses.

SECTION B

Answer any FIVE questions (5×8 =40)

Nine patients with severe chronic airflow limitation were the subjects of a study and Investigated the effectiveness of a treatment to improve gas exchange in subjects. The following are the body surface areas(m²) of the patients.

2.10 1.74 1.68 1.83 1.57 1.71 1.73 1.74 1.72

Calculate Mean, Standard Deviation and Co-efficient of Variation from the above data.

Explain any two types of classifications of data with illustrations.
If the average number of deaths from a certain non-contagious disease has been 5 and follow Poisson distribution for several years in the past. Find the probability that there will be:

[a] Exactly 3 people will die from the disease. [b] No deaths from the disease

Explain the step-by-step procedure of Hypothesis testing by an Illustration.
The Body Mass Index(BMI) measurements for 10 male subjects are given below:

Test if it is reasonable to conclude that the mean BMI of the population from the sample was drawn is more than 30? Let a=0.05

36, 38, 27, 28, 24, 32, 57, 28, 31, 42.

In a study on the effectiveness of Chicken-Kunya vaccine series , it is found that 610 of 650 vaccinated adults were not infected. However, 10 of 50 non-vaccinated adults were infected with Chicken-Kunya. Can we conclude on the basis of these sample data that the infection rate is significantly more in the non-vaccinated population than in the vaccinated population? Test at 5% level of Significance.
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 a=0.05

Before : 104 96 103 105 100 87 85 72

After : 89 78 89 83 77 67 60 69

Write a short note on the following measures :

[a] Central tendency [b] Dispersion [c] Skewness [d] Kurtosis

SECTION C

Answer any TWO questions (2×20=40)

In a research study, Age and Blood Urea values were observed from 10 PKD patients.

[a] Detect the nature of Correlation between Age and Blood urea level

[b] Determine the co-efficient of Correlation between Age and Blood Urea.

[c] Construct Regression equations and hence estimate the Blood Urea value

when age is 57

Age	13	12	38	15	37	33	34	36	78	61
Blood Urea	24	31	45	31	42	32	38	38	43	32

Blood Sugar values were observed from 10 Normal and 10 PKD patients. [a] Identify which set of patients is having higher average Blood sugar level. [b] Find out the group which is more consistent with regard to Blood Sugar level

[c] Also compute the co-efficients of Skewness and Kurtosis and hence

comment on symmetry and Normality nature of the groups.

Blood Sugar (Normal)	130	155	185	98	120	106	125	96	110	90
Blood Sugar (PKD)	180	125	162	140	162	130	108	145	190	125

[a] The following are measurements of Streptococcus Pneumonia bacteria in lungs ( log₁₀ cfu / ml of lung homogenate) after 24 hours of injections of two types. Can we conclude that the injections are equally effective on the clearance of the viable bacteria? Test at 5% level of significance.

Ofloxacin100 : 7.3 5.3 7.4 6.7 7.1

Ciprofloxacin100 : 7.8 4.6 6.4 8.0 7.2

[b] The following table gives the number of earthworms obtained from ten randomly

located sampled plots of 1m² area. Can we conclude that the earthworm

population is distributed equally in all the plots?

Plot number	1 2 3 4 5 6 7 8 9 10
No. of Earthworm / m²	25 32 17 23 15 39 27 19 22 26

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 motivation	Re-motivation method A B C D E
Nil	58	68	60	68	64
Very Low	62	70	65	80	69
Low	67	78	68	81	70
Average	70	81	70	89	74

Do these data provide sufficient evidence to indicate a difference in mean scores among methods? Also, test whether the level of Initial motivation are equal?

Let a=0.05.

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