leiyou

 

The correct answer is B

Decision rule: reject H0 if zcomputed < –1.96, or zcomputed > +1.96. Since –2.67 < –1.96 , reject H0

leiyou

 

The correct answer is C

The normally distributed test statistic is:

 

[attach]13862[/attach]

leiyou

 

The critical z-value(s) of the test statistic is (are):

A) ± 1.96.

B) –1.96.

C) +1.96.

D) ± 2.58.

leiyou

 

The correct answer is D

H0: μ = 3 hours.

leiyou

 

Which type of test is this?

A) One-tailed test. 

B) Chi-square test.

C) Equity of variance test.

D) Two-tailed test.

leiyou

 

The correct answer is D

This is a two-sided (tailed) test. We want to test if the mean “differs from” 3 hours (i.e., Ha: μ ≠ 3 hours).

leiyou

 

The calculated z-statistic is:

A) –2.13.

B) +0.33.

C) –2.67.

D) +2.67.

leiyou

 

The correct answer is C

The statement shows a preference for not rejecting the null hypothesis when it is false (a type II error), over rejecting it when it is true (a type I error).

leiyou

 

4、Which of the following statements about hypothesis testing is least accurate?

A) If the alternative hypothesis is Ha: μ > μ0, a two-tailed test is appropriate.

B) The null hypothesis is a statement about the value of a population parameter.

C) A Type II error is failing to reject a false null hypothesis.

D) A Type I error is rejecting the null hypothesis when it is actually true.

leiyou

 

The correct answer is A

The hypotheses are always stated in terms of a population parameter. Type I and Type II are the two types of errors you can make – reject a null hypothesis that is true or fail to reject a null hypothesis that is false. The alternative may be one-sided (in which case a > or < sign is used) or two-sided (in which case a ≠ is used).