SRM University 2007 B.Tech Bioinformatics BANK MA 262 BIO STATISTICS - Question Paper

ques. BANK
MA 262
BIO STATISTICS
UNIT: III
TESTING OF HYPOTHESIS

PART A

1. What is meant by testing of hypothesis?
2. Define sampling distribution and standard fault.
3. Define null and option hypothesis.
4. Explain the procedure involved in testing of hypothesis.
5. With the help of examples, contrast ranging from null and option hypothesis.
6. What is meant by (i) critical region (ii) level of significance?
7. Define kind I and kind II errors.
8. Define one-tailed and two-tailed tests with suitable examples.
9. Define confidence limits.
10. What is the standard fault of the sample proportion when the population proportion is (i) known (ii) not known?
11. Write down the 95% confidence limits for the unknown population mean in terms of the (i) population standard deviation and (ii) sample standard deviation
12. Define ?2 - distribution and state its properties.
13. State the conditions for the validity of ?2 - test for goodness of fit.
14. What is ?2 - test for independence of attributes?
15. State the assumptions under t – distribution
16. Explain the situation under which paired t – test is to be employed
17. State the important properties of F – distribution
18. State the applications of t – test & F – test.
19. How will you get the critical value of ‘t’ for a single – tailed test at LOS ? ?
20. What is the test statistic used to test the significance of the difference ranging from small sample mean and population mean ?
21. Give the 95% confidence interval of the population mean interms of the mean and the S.D. of the small sample.
22. What is the test statistic used to test the significance of the difference ranging from the means of 2 small samples ?

PART B
1. The mean yield of 2 sets of plots and their variability are as provided beneath.


Set of 40 plots Set of 60 plots
Mean yield per plot 1258 Kg 1243 Kg
S.D per plot 34 Kg 28 Kg
Examine (a) whether the difference in the mean yields of the 2 sets plots is
significant and (b) whether the difference in the variability in yields is significant.
2. The annual rainfall at a certain place is normally distributed with mean 30.If the rainfalls during the past eight years are 31.1, 30.7, 24.3, 28.1, 27.9, 32.2, 25.4 & 29.1. Can we conclude that avg. rainfall during the past eight years is less than the normal rainfall ?
3. A Random sample of eight envelopes taken from the letter box of a post office had
respective weights, 12.2, 11.9, 12.5, 12.3, 11.6, 11.7, 12.2 & 12.4 gms.Find the 95 & 99
% fiducial limits for the mean weight of the envelopes.
3. A machinist is expected to make engine parts with axle diameter of 1.75 cm. A random sample of 10 parts indicates a mean diameter of 1.85 cms , with a SD of 0.1 cm. On the basis of this sample, would you say that the work of the machinist is inferior ?

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