LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc. DEGREE EXAMINATION – STATISTICS
FIFTH SEMESTER – NOVEMBER 2012
ST 5505/ST 5501 – TESTING OF HYPOTHESES
Date : 03/11/2012 Dept. No. Max. : 100 Marks
Time : 9:00 – 12:00
PART – A
Answer ALL Questions: ( 10 x 2 = 20 Marks )
- Distinguish between Simple and Composite hypotheses.
- Define Best Critical Region.
- Define Exponential Distribution.
- When do you call a test uniformly most powerful?
- Define SPRT for testing Ho against H1.
- State the ASN function for the SPRT for testing Ho: q = q0 against H1: q = q1.
- What do you mean by one-tailed and two-tailed tests?
- State the assumptions for Student’s t-test.
- Mention the assumptions associated with Non-parametric tests.
- State the situations where Sign test can be applied.
PART – B
Answer any FIVE questions: ( 5 x 8 = 40 Marks )
- Explain the concept of critical region.
12 Define and elaborate two types of errors in testing of hypothesis.
- Discuss the general approach of likelihood ratio test.
- Find the LRT of Ho: q = q0 against H1: q ≠ qo based on sample of size 1 from the density
f ( x, q ) = 2 ( q – x ) / q2 , 0 < x < q
- Explain the concepts
- i) Level of Significance
- ii) Null and Alternative hypotheses.
- A manufacturer of dry cells claimed that the life of their cells is 24.0 hours. A sample of
10 cells had mean life of 22.5 hours with a standard deviation of 3.0 hours. On the basis of
available information, test whether the claim of the manufacturer is correct.
17 In a breeding experiment, the ratio of off-spring in four classes was expected to be 1:3:3:9.
The experiment yielded the data as follows:
Classes AA Aa aA aa
No.of offsprings: 8 29 37 102
Test whether the given data is in agreement with the hypothetical ratio.
- Use the sign test to see if there is a difference between the number of days required to collect
an account receivable before and after a new collection policy. Use the 00.5 significance level
Before: 33 36 41 32 39 47 34 29 32 34 40 42 33 36 27
After : 35 29 38 34 37 47 36 32 30 34 41 38 37 35 28
PART – C
Answer any TWO questions: (2 x 20 = 40 Marks )
19 a) State and Prove Neymann-Pearson Lemma.
- b) A sample of size 1 is taken from density
f ( x, q ) = 2 ( q – x ) / q2 , 0 < x < q
= 0 else where
Find an Most Powerful test of Ho: q = q0 versus H1: q = q1 ; q0 > q1 at level α .
20 a) Describe the sequential procedure for testing Ho: q = q0 against H1: q ≠ q1 where q is the
parameter of the Poisson distribution.
- b) The heights of ten children selected at random from a given locality had a mean 63.2 cms
and variance 6.25 cms. Test at 5 % level of significance the hypothesis that the children of
the given locality are on the average less than 65 cms in all. Given for 9 degrees of freedom
P( t.> 1.83) = 0.05.
- a) Explain Chi-square test of Goodness of fit.
- b) The following table gives the number of aircraft accidents that occurred during the seven
days of the week. Find whether the accidents are uniformly distributed over the week.
Days : Mon Tue Wed Thur Fri Sat Total
No.of accidents : 14 18 12 11 15 14 84
- a) Find 99 % confidence limits for the parameter l in Poisson distribution.
- b) Apply Median Test for the following data:
X: 27 31 32 33 34 29 35
Y: 28 30 30 24 25 26
Latest Govt Job & Exam Updates: