1. The mean life of 500 bulbs, as obtained in a random sample manufactured by a company, was found to be 900 hours with a standard deviation of 300 hours. Test the hypothesis that the mean life is less than 900 hours. Select α = 0.05
A. Z = 2.356
B. Z = -2.3567
C. Z = 1.789
D. Z = 3.7268
2. A family-planning activist claims that more than 33 per cent of the families in her town have more than one child. A random sample of 160 families from the town reveals that 50 families have more than one child. Select α = 0.01. Calculate z score.
A. Z = -0.5623
B. Z = 0.2356
C. Z = -0.4708
D. Z = 0.3658
3. A sample is considered as small if its size is
A. 50 or less
B. 30 or less
C. 30 or more
D. 70 or less
4. On the basis of sample size, tests can be
A. Exact tests and
B. Approximate tests
C. Both (a) and (b)
D. Neither (a) nor (b)
5. The sample with size exceeding 30 is considered as a
A. Large sample
B. Huge sample
C. Small sample
D. None of the above
6. A sample is considered as large if its size is
A. 50 or less
B. 30 or less
C. More than 30
D. 70 or less
7. …………………… are those tests that are based on the exact sampling distribution of the test statistic and no approximation is made about the form of parent population or the sampling distribution of the test statistic
A. Exact tests
B. Approximate tests
C. Large sample tests
D. None of the above
8. Approximate tests are also known as
A. Exact tests
B. Small sample tests
C. Large sample tests
D. None of the above
9. Exact tests are valid for ………… sample size
A. Any
B. Large
C. Small
D. None of the above
10. Exact tests are also known as
A. Approximate tests
B. Small sample tests
C. Large sample tests
D. None of the above
11. While testing for population mean on the basis of a random sample from a normal distribution, we apply ……………… provided the population standard deviation is known
A. Large sample tests
B. Approximate tests
C. Exact tests
D. None of the above
12. The sample with size 30 or less is considered as a
A. Large sample
B. Mini sample
C. Small sample
D. None of the above
13. Which of the following is a non-parametric test?
A. Paired sample t-test
B. One way ANOVA
C. Mann-Whitney test
D. Pearson correlation
14. These tests make assumptions about the parameters of the population distribution from which the sample is drawn
A. Non-parametric
B. Parametric
C. Both (a) and (b)
D. Neither (a) nor (b)
15. Which of the following is not a parametric test?
A. Paired sample t-test
B. Independent sample t-test
C. Kruskal-Wallis test
D. One way ANOVA
16. Which tests are “distribution-free”?
A. Non-parametric
B. Parametric
C. Both (a) and (b)
D. Neither (a) nor (b)
17. Which of the following is a parametric test?
A. Independent sample t-test
B. Paired sample t-test
C. One way ANOVA
D. All of the above
18. What are the advantages of parametric tests?
A. These tests can provide trustworthy results with distributions that are skewed and non-normal
B. These tests can provide trustworthy results when the groups have different amounts of variability
C. These tests have greater statistical power
D. All of the above
19. Which of the following is not a non-parametric test?
A. Kruskal-Wallis test
B. Paired sample t-test
C. Mann-Whitney test
D. Friedman’s ANOVA
20. What are the advantages of non-parametric tests?
A. These tests assess the median which can be better for some study areas
B. These tests are valid when our sample size is small and your data are potentially non-normal
C. These tests can analyze ordinal data, ranked data, and outliers
D. All of the above