SRM University 2007 B.Tech Bioinformatics BANK MA262 (BIO STATISTICS) - Question Paper

S.R.M.INSTITUTE OF SCIENCE & TECHNOLOGY
II – YEAR B.TECH – BIO-INFORMATICS
ques. BANK
MA262 (BIO STATISTICS)
UNIT: I
INTRODUCTION TO BIO-STATISTICS
PART-A
1. Define measure of central tendency and state any 2 measures.
2. What are the requisites for an ideal measure of central tendency?
3. Define Arithmetic mean and state any 2 properties.
4. Write the formula for finding the arithmetic mean provided
(i)’n’ observations and
(ii)fi the frequency for xi =1,2,…n
5. The mean of 20 observations is 15.On checking it was obtained that 2 observations were wrongly copied as three and six instead of eight and 4.Find the corrected mean.
6. Find the median of xi:1, 2, 3, 4, 5, 6, 7, 8, 9
fi: 8, 10, 11, 16, 20, 25, 15, 9, 6
7. Write the formula for finding the mode in case of a continuous frequency distribution.
8. Define Harmonic mean and provide its applications.
9. Give the relationship ranging from
(i)mean,median,mode
(ii)A.M,G.M,H.M.
10. Find the simple and weighted arithmetic mean of the first’n’ natural numbers,the weights being the corresponding numbers.
11. What is meant by measures of Dispersion? provide any two measures.
12. Write the formula for finding the geometric mean and harmonic mean in case of a discrete frequency distribution
13. Which is best method of Dispersion and why?
14. From the data provided beneath write which firm is more consistent
Firm A Firm B
avg. monthly wages Rs: 186 Rs: 175

Variance 81 100
PART-B

1. Obtain mean, median and mode for the subsequent data
values: 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50
frequency: two 28 125 270 303 197 65 10
2. The geometric mean of 10 observations on a certain variable was computed as 16.2.It was later discovered that 1 of the observation was wrongly recorded as 12.9, infact it was 21.9.Calculate the corrected geometric mean.
3. The avg. salary of male employees in a firm was Rs 520 and that of female employees was Rs420.The mean salary of are the employees was Rs500.Find the percentage of male and female Employees .
4. A train runs 25 miles at a speed of 30m.p.h a different 50 miles at a speed of 40m.p.h and finally the remaining distance of 24 miles at a speed of 24m.p.h.what is the avg. speed?
5. Find the missing frequency from the subsequent
variable:10-20 20-30 30-40 40-50 50-60 60-70 70-80
frequency: 12 30 ? 65 ? 25 18
provided that N=229 and median is 46.
6. Calculate the Quartile deviation and the coefficient of Quartile deviation from the subsequent data
Heights in inches: 50 51 52 53 54 55 56
Frequency: 10 12 15 10 14 18 6
7. Find the arithmetic mean and standard deviation for the subsequent
x: 2.5-7.5 7.5-12.5 12.5-17.5 17.5-22.5 22.5-27.5 27.5-32.5 32.5-37.5
f: 12 28 65 121 175 198 176

x: 37.5-42.5 42.5-47.5 47.5-52.5 52.5-57.5 57.5-62.5
f: 120 66 27 nine 3
8. The means of 2 samples of size 50 and 100 respectively are 54.1 and 50.3 and the standard deviations are eight and seven .Obtain the mean and standard deviation of the sample of size 150 found by combining the 2 samples.
9. The 1st of the 2 samples has 100 items with mean 15 and standard deviation 3. If the whole group has 250 items with mean 15.6 and standard deviation?13.44.Find the S.D of the 2nd group.

Earning:   Approval pending.