Q1. Student’s ‘t’ distribution was found by
a) Karl Pearson
b) Laplace
c) R.A. Fisher
d) William S.Gosset
Answer: d) William S.Gosset
Q2. Support of student’s t random variable is
Answer c
Q3. Paired t-test is applicable when the observations in both the samples are
a) Paired
b) Correlated
c) Equal in number
d) all the above
Answer: d) all the above
Q4. The number of degrees of freedom for the test statistic
a) n – 1
b) n
c) n – 2
d) n + 1
Answer: a) n – 1
Q5. Standard error of difference between two sample means in the case of small samples is
Answer C
Q6. If the size of sample is larger than 30, the t-distribution tends to
a) normal distribution
b) F-distribution
c) chi-square distribution
d) Poisson distribution
Answer a) normal distribution
Q7. If a random sample of 10 observations has variance 324 then standard error is
a) 18/√10
b) 18/10
c) 10/18
d) 2/ √5
Answer: a) 18/√10
Q8. A sample of 16 units was taken for testing an hypothesis concerning the mean of a normal population. Then the degrees of freedom of the appropriate test statictic is
a) 14
b) 15
c) 16
d) 8
Correct Answer c) 16
Q9. If s12 and s22 are respectively the variance of two independent random samples of sizes ‘m’ and ‘n’. Then standard deviation of the combined sample is
Correct Answer D
Q10. A company gave an intensive training to its salesman to increase the sales. A random sample of 6 salesmen was selected and the value of their sales made before and after the training is recorded. Which test will be more appropriate to test whether there is an increase in mean sales
a) normal test
b) paired t-test
c) χ2-test
d) F-test
Answer: b) paired t-test
Q11. If the order of the contigency table is (5 × 4). Then the degree of freedom of the corresponding chi-square test statistic is
a) 18
b) 17
c) 12
d) 25
Correct Answer c) 12
Q12. For testing the hypothesis concerning variance of a normal population ——————- is used.
a) t-test
b) F-test
c) Z-test
d) χ2-test
Correct Answer d) χ2-test
Q13. If σ2 is the variance of normal population, then the degrees of freedom of the sampling distribution of the test statistic for testing H0 : σ2 = σ02
a) n–1
b) n+1
c) n
d) n–2
Answer: a) n–1
Q14. If n is the degree of freedom of chi-square distribution then its variance is
a) n
b) n–1
c) 2n
d) n+1
Correct Answer c) 2n
Q15. If chi-square is performed for testing goodness of fit to a data with k classes on estimating ‘s’ parameters then degrees of fredom of test statistic is.
a) k–s
b) (k–1)(s–1)
c) k–1–s
d) k–1
Correct Answer c) k–1–s
Q16. The statistic 2, with usual notations, in case of contingency table of order (m × n) is given by
Correct Answer A
