Question

Question #3

A researcher is conducting and experiment to evaluate a treatment that is expected to increase the scores for individuals in a population. If the researcher uses a one-tailed test with ( a = .01), then which of the following correctly identifies the critical region?

A. z > 2.33

B. z > 2.58

C. z < 2.33

D. z < 2.58

Question #4

A researcher evaluates a treatment effect using a two tailed hypothesis test with ( a = .05), and the decision is to reject the null hypothesis. If the researcher switched to a one-tailed test using the same sample, what decision would be made?

A. Definitely reject the null hypothesis with ( a = .05) and maybe reject with ( a = .01)

B. Definitely reject the null hypothesis with ( a = .05) and with ( a = .01)

C. Definitely fail to reject the null hypothesis with either (a = .05) or with ( a = .01)

D. It is impossible to predict the outcome of the one-tailed test.

Question #5

A researcher evaluates a treatment effect using a one-tailed hypothesis test with ( a = .05), and the decision is to reject the null hypothesis. If the researcher switched to a two-tailed test using the same sample, what decision would be made?

A. Definitely reject the null hypothesis with either ( a = .05) or with ( a = .01)

B. Definitely reject the null hypothesis with ( a = .05) and maybe reject with ( a = .01)

C. Might reject the null hypothesis with ( a = 0.5) but might not

D. Definitely fail to reject the null hypothesis with either ( a = .05) or with ( a = .01)

Answer 1

3) the critical value z_a at a =0.01 is determined form the standard normal table. Therefore z_a= 2.33. Then the critical region or rejection region is given by z>2.33. Option a is correct.

4) at two tailed test, the level of significance a=0.05. We reject the null hypothesis. The we defintilty reject the null hypothesis at level of significance a=0.05 but may not be a =0.01 in one tailed test.

Option a is correct.

5) in a one tailed test level of significance a=0.05, we reject the null hypothesis. But in two tailed test we may be rejected or fail to rejected the null hypothesis at a=0.05 & 0.01.

Option c is correct