Question 1

Elwin Osbourne,CIO at GFS,Inc. ,suspects that at least 25% of email messages sent by GFS employees are not business related.A random sample of 300 email messages was selected to test this hypothesis at the 0.01 level of significance.Fifty-four of the messages were not business related.The appropriate decision is __.

Accepted Answer

A) increase the sample size 
B) gather more data 
C) reject the null hypothesis 
D) do not reject the null hypothesis 
E) maintain status quo

Question 2

If the researcher computes the probability of the calculated statistic and compares it to alpha,the level of significance to reach a decision,the researcher is using the p-value method for testing the hypotheses.

Accepted Answer

A) True 
 B)False

Question 3

The diameter of 3.5 centimetre discs is normally distributed.Periodically,quality control inspectors at Winnipeg Discs randomly select a sample of 16 discs.If the mean diameter of the discs is too large or too small the disc punch is shut down for adjustment;otherwise,the punching process continues.The last sample showed a mean and standard deviation of 3.55 and 0.08 centimetres,respectively.Using  $\alpha$ = 0.05,the appropriate decision is ___.

Accepted Answer

A) reject the null hypothesis and shut down the punch 
B) reject the null hypothesis and do not shut down the punch 
C) do not reject the null hypothesis and shut down the punch 
D) do not reject the null hypothesis and do not shut down the punch 
E) do nothing

Question 4

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and a two-tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

Accepted Answer

A) reject 
B) not reject 
C) redefine 
D) change the alternate hypothesis into 
E) restate the null hypothesis

Question 5

A company believes that it controls more than 30% of the total market share for one of its products.To prove this belief,a random sample of 144 purchases of this product is contacted.It is found that 50 of the 144 purchased this company's brand of the product.If a researcher wants to conduct a statistical test for this problem,the alternative hypothesis would be ___.

Accepted Answer

A) the population proportion is less than 0.30 
B) the population proportion is greater than 0.30 
C) the population proportion is not equal to 0.30 
D) the population mean is less than 40 
E) the population mean is greater than 40

Question 6

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and an one?tailed test is 1.645.The observed z value from sample data is 1.13.The decision made by the researcher based on this information is to ___ the null hypothesis.

Accepted Answer

A) reject 
B) not reject 
C) redefine 
D) change the alternate hypothesis into 
E) restate the null hypothesis

Question 7

Suppose you are testing the null hypothesis that a population mean is less than or equal to 80,against the alternative hypothesis that the population mean is greater than 80.If the sample size is 49 and alpha = .10,the critical value of z is ___.

Accepted Answer

A) 1.645 
B) -1.645 
C) 1.28 
D) -1.28 
E) 2.33

Question 8

If a null hypothesis was not rejected at the 0.10 level of significance,it will be rejected at a 0.05 level of significance based on the same sample results.

Accepted Answer

A) True 
 B)False

Question 9

The rejection region for a hypothesis test becomes smaller if the level of significance is changed from 0.01 to 0.05.

Accepted Answer

A) True 
 B)False

Question 10

Suppose you are testing the null hypothesis that a population mean is greater than or equal to 60,against the alternative hypothesis that the population mean is less than 60.The sample size is 64 and $\alpha$ = .05.If the sample mean is 58 and the population standard deviation is 16,the observed z value is ___.

Accepted Answer

A) -1 
B) 1 
C) -8 
D) 8 
E) 58

Question 11

Whenever hypotheses are established such that the alternative hypothesis is "not equal to",the hypothesis test would be a two-tailed test.

Accepted Answer

A) True 
 B)False

Question 12

When a false null hypothesis is rejected,the researcher has made a Type II error.

Accepted Answer

A) True 
 B)False

Question 13

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and a two-tailed test is +1.96.The observed z value from sample data is -1.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

Accepted Answer

A) reject 
B) not reject 
C) redefine 
D) change the alternate hypothesis into 
E) restate the null hypothesis

Question 14

In performing a hypothesis test where the null hypothesis is that the population mean is 6.9 against the alternative hypothesis that the population mean is not equal to 6.9,a random sample of 16 items is selected.The sample mean is 7.1 and the sample standard deviation is 2.4.It can be assumed that the population is normally distributed.The level of significance is selected as 0.05.The decision rule for this problem is to reject the null hypothesis if the observed "t" value is ___.

Accepted Answer

A) less than -2.131 or greater than 2.131 
B) less than -1.761 or greater than 1.761 
C) less than -1.753 or greater than 1.753 
D) less than -2.120 or greater than 2.120 
E) less than -3.120 or greater than 3.120

Question 15

Consider the following null and alternative hypotheses: Ho: µ $\le$ 67
Ha: µ > 67
These hypotheses ___.

Accepted Answer

A) indicate a one-tailed test with a rejection area in the right tail 
B) indicate a one-tailed test with a rejection area in the left tail 
C) indicate a two-tailed test 
D) are established incorrectly 
E) are not mutually exclusive

Question 16

Consider the following null and alternative hypotheses: Ho: p = 0.16
Ha: p $\neq$ 0.16
These hypotheses ___.

Accepted Answer

A) indicate a one-tailed test with a rejection area in the right tail 
B) indicate a one-tailed test with a rejection area in the left tail 
C) indicate a two-tailed test 
D) are established incorrectly 
E) are not mutually exclusive

Question 17

In a two-tailed hypothesis about a population mean with a sample size of 100 and α = 0.05,the rejection region would be ___.

Accepted Answer

A) z > 1.64 
B) z > 1.96 
C) z  1.96 
D) z  1.64 
E) z  2.33

Question 18

Reach a statistical conclusion in hypothesis testing problems about a population mean with a known population standard deviation using the z statistic.

Accepted Answer

The answer of Reach a statistical conclusion in hypothesis testing...

Question 19

A company believes that it controls more than 30% of the total market share for one of its products.To prove this belief,a random sample of 144 purchases of this product is contacted.It is found that 50 of the 144 purchased this company's brand of the product.If a researcher wants to conduct a statistical test for this problem,the test would be ___.

Accepted Answer

A) a one-tailed test 
B) a two-tailed test 
C) an alpha test 
D) a finite population test 
E) a finite sample test

Exam 9: Statistical Inference: Hypothesis Testing for Single Populations

If the researcher computes the probability of the calculated statistic and compares it to alpha,the level of significance to reach a decision,the researcher is using the p-value method for testing the hypotheses.

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and a two-tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and an one?tailed test is 1.645.The observed z value from sample data is 1.13.The decision made by the researcher based on this information is to ___ the null hypothesis.

Suppose you are testing the null hypothesis that a population mean is less than or equal to 80,against the alternative hypothesis that the population mean is greater than 80.If the sample size is 49 and alpha = .10,the critical value of z is ___.

If a null hypothesis was not rejected at the 0.10 level of significance,it will be rejected at a 0.05 level of significance based on the same sample results.

The rejection region for a hypothesis test becomes smaller if the level of significance is changed from 0.01 to 0.05.

Whenever hypotheses are established such that the alternative hypothesis is "not equal to",the hypothesis test would be a two-tailed test.

When a false null hypothesis is rejected,the researcher has made a Type II error.

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and a two-tailed test is +1.96.The observed z value from sample data is -1.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

Consider the following null and alternative hypotheses: H_o: µ $\le$ 67 H_a: µ > 67 These hypotheses ___.

Consider the following null and alternative hypotheses: H_o: p = 0.16 H_a: p $\neq$ 0.16 These hypotheses ___.

In a two-tailed hypothesis about a population mean with a sample size of 100 and α = 0.05,the rejection region would be ___.

Reach a statistical conclusion in hypothesis testing problems about a population mean with a known population standard deviation using the z statistic.

Exam 9: Statistical Inference: Hypothesis Testing for Single Populations

If the researcher computes the probability of the calculated statistic and compares it to alpha,the level of significance to reach a decision,the researcher is using the p-value method for testing the hypotheses.

A researcher is testing a hypothesis of a single mean.The critical z value for α\alphaα = .05 and a two-tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

A researcher is testing a hypothesis of a single mean.The critical z value for α\alphaα = .05 and an one?tailed test is 1.645.The observed z value from sample data is 1.13.The decision made by the researcher based on this information is to ___ the null hypothesis.

Suppose you are testing the null hypothesis that a population mean is less than or equal to 80,against the alternative hypothesis that the population mean is greater than 80.If the sample size is 49 and alpha = .10,the critical value of z is ___.

If a null hypothesis was not rejected at the 0.10 level of significance,it will be rejected at a 0.05 level of significance based on the same sample results.

The rejection region for a hypothesis test becomes smaller if the level of significance is changed from 0.01 to 0.05.

Whenever hypotheses are established such that the alternative hypothesis is "not equal to",the hypothesis test would be a two-tailed test.

When a false null hypothesis is rejected,the researcher has made a Type II error.

A researcher is testing a hypothesis of a single mean.The critical z value for α\alphaα = .05 and a two-tailed test is +1.96.The observed z value from sample data is -1.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

Consider the following null and alternative hypotheses: Ho: µ ≤\le≤ 67 Ha: µ > 67 These hypotheses ___.

Consider the following null and alternative hypotheses: Ho: p = 0.16 Ha: p ≠\neq= 0.16 These hypotheses ___.

In a two-tailed hypothesis about a population mean with a sample size of 100 and α = 0.05,the rejection region would be ___.

Reach a statistical conclusion in hypothesis testing problems about a population mean with a known population standard deviation using the z statistic.

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and a two-tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and an one?tailed test is 1.645.The observed z value from sample data is 1.13.The decision made by the researcher based on this information is to ___ the null hypothesis.

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 and a two-tailed test is +1.96.The observed z value from sample data is -1.85.The decision made by the researcher based on this information is to ___ the null hypothesis.

Consider the following null and alternative hypotheses: H_o: µ $\le$ 67 H_a: µ > 67 These hypotheses ___.

Consider the following null and alternative hypotheses: H_o: p = 0.16 H_a: p $\neq$ 0.16 These hypotheses ___.