leiyou

 

2、A goal of an “innocent until proven guilty” justice system is to place a higher priority on:

A) avoiding type I errors. 

B) avoiding type II errors.

C) avoiding type III errors.

D) the null hypothesis.

leiyou

 

The correct answer is A

In an “innocent until proven guilty” justice system, the null hypothesis is that the accused is innocent. The hypothesis can only be rejected by evidence proving guilt beyond a reasonable doubt, favoring the avoidance of type I errors.

leiyou

 

3、If the null hypothesis is innocence, then the statement “It is better that the guilty go free, than the innocent are punished” is an example of preferring a:

A) type I error over a type II error.

B) two tailed test over a one tailed test.

C) type II error over a type I error. 

D) higher level of significance.

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).

leiyou

 

5、An analyst is conducting a hypothesis test to determine if the mean time spent on investment research is different from 3 hours per day. The test is performed at the 5 percent level of significance and uses a random sample of 64 portfolio managers, where the mean time spent on research is found to be 2.5 hours. The population standard deviation is 1.5 hours.

The appropriate null hypothesis for the described test is:

A) H0: μ ≠ 3 hours.

B) H0: μ ≤ 3 hours.

C) H0: μ ≥ 3 hours.

D) H0: μ = 3 hours.

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).