leiyou

 

The correct answer is B

For a two-tailed test at a 1% level of significance, the critical values are +/?2.58.

leiyou

 

AIM 14: Define, calculate and interpret the test of significance approach to hypothesis testing.

1、In a two-tailed test of a hypothesis concerning whether a population mean is zero, Jack Olson computes a t-statistic of 2.7 based on a sample of 20 observations where the distribution is normal. If a 5% significance level is chosen, Olson should:

A) not make a conclusion pending additional observations.

B) reject the null hypothesis and conclude that the population mean is not significantly different from zero.

C) fail to reject the null hypothesis that the population mean is not significantly different from zero.

D) reject the null hypothesis and conclude that the population mean is significantly different from zero.

leiyou

 

The correct answer is D

At a 5% significance level, the critical t-statistic using the Student’s t-distribution table for a two-tailed test and 19 degrees of freedom (sample size of 20 less 1) is ± 2.093 (with a large sample size the critical z-statistic of 1.960 may be used). Because the critical t-statistic of 2.093 is to the left of the calculated t-statistic of 2.7, meaning that the calculated t-statistic is in the rejection range, we reject the null hypothesis and we conclude that the population mean is significantly different from zero.

leiyou

 

2、A survey is taken to determine whether the average starting salaries of CFA charterholders is equal to or greater than $59,000 per year. What is the test statistic given a sample of 135 newly acquired CFA charterholders with a mean starting salary of $64,000 and a standard deviation of $5,500?

A) 0.91.

B) -10.56.

C) -0.91.

D) 10.56.

leiyou

 

The correct answer is D

With a large sample size (135) the z-statistic is used. The z-statistic is calculated by subtracting the hypothesized parameter from the parameter that has been estimated and dividing the difference by the standard error of the sample statistic. Here, the test statistic = (sample mean – hypothesized mean) / (population standard deviation / (sample size)1/2) = (X ? μ) / (σ / n1/2) = (64,000 – 59,000) / (5,500 / 1351/2) = (5,000) / (5,500 / 11.62) = 10.56.

leiyou

 

The correct answer is D

The alternative hypothesis is determined by the theory or the belief. The researcher specifies the null as the hypothesis that she wishes to reject (in favor of the alternative). Note that this is a one-sided alternative because of the “greater than” belief.

leiyou

 

AIM 12: Distinguish between one-sided and two-sided hypotheses.

1、Using the following hypothesis and data:

?            H0: a = b and H1: a ≠ b

?            The critical Z-statistic is 2.58

?            The calculated Z-statistic is 4.1

An analyst should:

A) Reject the null hypothesis and conclude that a = b.

B) Reject the null hypothesis and conclude that a is significantly different than b.

C) Reject the alternative hypothesis and conclude that a = b.

D) Fail to reject the null hypothesis and conclude that we cannot say that a is significantly different than b.

leiyou

 

The correct answer is B

When the calculated Z > the critical Z (4.1 > 2.58), the null hypothesis should be rejected and the conclusion is made that a is not equal to b.

leiyou

 

2、Which of the following statements is FALSE?

A) For a one-tailed test at the 5% level of significance, the critical z-value is 1.645.

B) For a two-tailed test at the 1% level of significance, the critical z-values are +/?2.33.

C) The standard error of the sample mean may be expressed as s / √n.

D) The calculated z-statistic for a sample mean is (x ? μ) / (σ / √n).

leiyou

 

You should:

A) accept the null hypothesis.

B) reject the null hypothesis.

C) reject the alternative hypothesis.

D) Cannot be determined with the information given.