# Multiple Choice Answers

1) What are the critical z-values for a two-tailed hypothesis test if the significant level = 0.01?
A. ± 1.96
B. ± 2.33
C. ± 2.58
D. ± 1.65

2) In classical hypothesis testing, the test statistic is to the critical value what the __________.
A. ‘p-value’ is to alpha
B. critical value is to alpha
C. test statistic is to the ‘p-value’
D. level of significance is to the test statistic

3) For a hypothesis test of a single population mean at 95% confidence level, a calculated Z score of 1.7 supports the conclusion that
A. the population mean is greater than the hypothesized value
B. the null hypothesis cannot be rejected
C. the sample is biased
D. the population mean is less than expected

4) One hundred women were polled and 60 reported successfully communicating an automobile problem to an auto repairman. A sample of 150 men had 95 reporting the same success. The value of the test statistic for a test of the equality of proportions is
A. -0.5319
B. 0.7293
C. -0.419
D. 0.2702

5) Weekly sales of iPods® at 20 Best Buy® stores are compared before and after installing a new eye-catching display. To determine if the display is effective in increasing sales, what type of statistical test would you perform?
A. Comparison of means using independent samples using a t-test
B. Comparison of proportions using independent samples using a z-test
C. Comparison of means using a paired z-test
D. Comparison of means using a paired t-test

6) When is it appropriate to use the paired difference t-test?
A. Four samples are compared at once.
B. Any two samples are compared.
C. Two independent samples are compared.
D. Two dependent samples are compared.