Question

Multiple Choice:

Question #1

A two tailed hypothesis test is being used to evaluate a treatment effect with ( a = .05). if the sample data produce a Z-score of ( z= -2.24), what is the correct decision?

A. Reject the null hypothesis and conclude that the treatment has no effect

B. Reject the null hypothesis and conclude that the treatment has an effect

C. Fail to reject the null Hypothesis and conclude that the treatment has no effect

D. Fail to reject the null hypothesis and conclude that the treatment has an effect

Question #2

The critical boundaries for a hypothesis test are ( z = +1.96 and -1.96). If the z-score for the sample data is ( z = -1.90), what is the correct statistical decision?

A. Fail to reject H1

B. Fail to reject H0

C. Reject H1

D. Reject H0

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

1)

The null and alternate hypothesis are:

H0: the treatment has no effect

Ha: the treatment has an effect

Since this is a two-tailed test, so. the p-value is given by:

Since p-value is less than 0.05, so we have sufficient evidence to reject the null hypothesis H0.

Thus we reject the null hypothesis and conclude that the treatment has an effect.

Hence option B is the correct option.