Chapter 9 Stats Test

When using Excel to calculate a p-value for an upper-tail hypothesis test, which of the following must be used? a. RAND b. 1 − NORM.S.DIST c. NORM.S.DIST d. Not enough information is given to answer this question.

1-NORM.S.DIST

Read the z statistic from the normal distribution table and circle the correct answer. A one-tailed test (upper tail) at a .123 level of significance; z = _____. a. 1.54 b. 1.96 c. 1.645 d. 1.16

1.16

Refer to Exhibit 9-3. The test statistic equals _____. a. .1714 b. .3849 c. -1.2 d. 1.2

1.2

Refer to Exhibit 9-6. The test statistic is _____. a. .80 b. .05 c. 1.25 d. 2.00

1.25

Read the t statistic from the table of t distributions and circle the correct answer. A two-tailed test, a sample of 20 at a .20 level of significance; t = _____. a. 1.328 b. 2.539 c. 1.325 d. 2.528

1.328

Read the t statistic from the table of t distributions and circle the correct answer. A one-tailed test (upper tail), a sample size of 18 at a .05 level of significance; t = _____. a. 2.12 b. 1.734 c. -1.740 d. 1.740

1.740

Refer to Exhibit 9-2. The test statistic is _____. a. 1.96 b. 1.64 c. 2.00 d. .056

2.00

Refer to Exhibit 9-4. The test statistic is _____. a. 1.96 b. 2.00 c. 1.645 d. .05

2.00

Refer to Exhibit 9-1. The test statistic equals _____. a. 2.3 b. .38 c. -2.3 d. -.38

2.3

Excel's __________ function can be used to calculate a p-value for a hypothesis test when σ is unknown. a. RAND b. T.DIST c. NORM.S.DIST d. Not enough information is given to answer this question.

T.DIST

A Type I error is committed when _____. a. a true alternative hypothesis is not accepted b. a true null hypothesis is rejected c. the critical value is greater than the value of the test statistic d. sample data contradict the null hypothesis

a true null hypothesis is rejected

The error of rejecting a true null hypothesis is _____. a. a Type I error b. a Type II error c. either a Type I or Type II error, depending on the situation d. committed when not enough information is available

a type 1 error

As a general guideline, the research hypothesis should be stated as the _____. a. null hypothesis b. alternative hypothesis c. tentative assumption d. hypothesis the researcher wants to disprove

alternative hypothesis

In order to test the hypotheses H0: μ ≤ 100 and Ha: μ > 100 at an α level of significance, the null hypothesis will be rejected if the test statistic z is _____. a. ≥ zα b. < zα c. ≤ -zα d. < 100

answer a

When the p-value is used for hypothesis testing, the null hypothesis is rejected if _____. a. p-value ≤ α b. α < p-value c. p-value > α d. p-value = z

answer a

The average life expectancy of tires produced by Whitney Tire Company has been 40,000 miles. Management believes that due to a new production process, the life expectancy of its tires has increased. In order to test the validity of this belief, the correct set of hypotheses is _____. a. H0: μ < 40,000 Ha: μ ≥ 40,000 b. H0: μ ≤ 40,000 Ha: μ > 40,000 c. H0: μ > 40,000 Ha: μ ≤ 40,000 d. H0: μ ≥ 40,000 Ha: μ < 40,000

answer b

The manager of an automobile dealership is considering a new bonus plan in order to increase sales. Currently, the mean sales rate per salesperson is five automobiles per month. The correct set of hypotheses for testing the effect of the bonus plan is _____. a. H0: μ < 5 Ha: μ ≤ 5 b. H0: μ ≤ 5 Ha: μ > 5 c. H0: μ > 5 Ha: μ ≤ 5 d. H0: μ ≥ 5 Ha: μ < 5

answer b

A student believes that the average grade on the final examination in statistics is at least 85. She plans on taking a sample to test her belief. The correct set of hypotheses is _____. a. H0: μ < 85 Ha: μ ≥ 85 b. H0: μ ≤ 85 Ha: μ > 85 c. H0: μ ≥ 85 Ha: μ < 85 d. H0: μ > 85 Ha: μ ≤ 85

answer c

The academic planner of a university thinks that at least 35% of the entire student body attends summer school. The correct set of hypotheses to test his belief is _____. a. H0: p > .35 Ha: p ≥ .35 b. H0: p ≤ .35 Ha: p > .35 c. H0: p ≥ .35 Ha: p < .35 d. H0: p > .35 Ha: p ≤ .35

answer c

The school's newspaper reported that the proportion of students majoring in business is at least 30%. You plan on taking a sample to test the newspaper's claim. The correct set of hypotheses is _____. a. H0: p < .30 Ha: p ≥ .30 b. H0: p ≤ .30 Ha: p > .30 c. H0: p ≥ .30 Ha: p < .30 d. H0: p > .30 Ha: p ≤ .30

answer c

When the hypotheses H0: μ ≥ 100 and Ha: μ < 100 are being tested at a level of significance of α, the null hypothesis will be rejected if the test statistic z is _____. a. > zα b. > -zα c. < -zα d. < 100

answer c

A meteorologist stated that the average temperature during July in Chattanooga was 80 degrees. A sample of July temperatures over a 32-year period was taken. The correct set of hypotheses is _____. a. H0: μ < 80 Ha: μ ≤ 80 b. H0: μ ≤ 80 Ha: μ > 80 c. H0: μ ≠ 80 Ha: μ = 80 d. H0: μ = 80 Ha: μ ≠ 80

answer d

A soft drink filling machine, when in perfect adjustment, fills the bottles with 12 ounces of soft drink. Any overfilling or underfilling results in the shutdown and readjustment of the machine. To determine whether or not the machine is properly adjusted, the correct set of hypotheses is _____. a. H0: μ < 12 Ha: μ ≤ 12 b. H0: μ ≤ 12 Ha: μ > 12 c. H0: μ ≠ 12 Ha: μ = 12 d. H0: μ = 12 Ha: μ ≠ 12

answer d

For a two-tailed hypothesis test about a population mean, the null hypothesis can be rejected if the confidence interval _____. a. is symmetric b. is non-symmetric c. includes µ0 d. does not include µ0

answer d

In the past, 75% of the tourists who visited Chattanooga went to see Rock City. The management of Rock City recently undertook an extensive promotional campaign. They are interested in determining whether the promotional campaign actually INCREASED the proportion of tourists visiting Rock City. The correct set of hypotheses is _____. a. H0: p > .75 Ha: p ≤ .75 b. H0: p < .75 Ha: p ≥ .75 c. H0: p ≥ .75 Ha: p < .75 d. H0: p ≤ .75 Ha: p > .75

answer d

Which of the following hypotheses is not a valid null hypothesis? a. H0: μ ≤ 0 b. H0: μ ≥ 0 c. H0: μ = 0 d. H0: μ < 0

answer d

Your investment executive claims that the average yearly rate of return on the stocks she recommends is at least 10.0%. You plan on taking a sample to test her claim. The correct set of hypotheses is _____. a. H0: μ < 10.0% Ha: μ ≥ 10.0% b. H0: μ ≤ 10.0% Ha: μ > 10.0% c. H0: μ > 10.0% Ha: μ ≤ 10.0% d. H0: μ ≥ 10.0% Ha: μ < 10.0%

answer d

Refer to Exhibit 9-1. If the test is done at a .05 level of significance, the null hypothesis should _____. a. not be rejected b. be rejected c. Not enough information is given to answer this question. d. None of the answers is correct.

be rejected

For a two-tailed test with a sample size of 40, the null hypothesis will NOT be rejected at a 5% level of significance if the test statistic is _____. a. between -1.96 and 1.96, exclusively b. greater than 1.96 c. less than 1.645 d. greater than -1.645

between -1.96 and 1.96, exclusively

For a one-tailed test (upper tail) with a sample size of 900, the null hypothesis will be rejected at the .05 level of significance if the test statistic is _____. a. less than or equal to -1.645 b. greater than or equal to 1.645 c. less than 1.645 d. less than -1.96

greater than or equal to 1.645

When the rejection region is in the lower tail of the sampling distribution, the p-value is the area under the curve _____. a. less than or equal to the critical value b. less than or equal to the test statistic c. greater than or equal to the critical value d. greater than or equal to the test statistic

greater than or equal to the critical value

The smaller the p-value, the _____. a. greater the evidence against H0 b. greater the chance of committing a Type II error c. greater the chance of committing a Type I error d. less likely one will reject H0

greater the evidence against H0

The practice of concluding "do not reject H0" is preferred over "accept H0" when we _____. a. are conducting a one-tailed test b. are testing the validity of a claim c. have an insufficient sample size d. have not controlled for the Type II error

have not controlled for the Type 2 error

An example of statistical inference is _____. a. a population mean b. descriptive statistics c. calculating the size of a sample d. hypothesis testing

hypothesis testing

In tests about a population proportion, p0 represents the _____. a. hypothesized population proportion b. observed sample proportion c. observed p-value d. probability of

hypothesized population proportion

A two-tailed test is a hypothesis test in which the rejection region is _____. a. in both tails of the sampling distribution b. in one tail of the sampling distribution c. only in the lower tail of the sampling distribution d. only in the upper tail of the sampling distribution

in both tails of the sampling distribution

A one-tailed test is a hypothesis test in which rejection region is _____. a. in both tails of the sampling distribution b. in one tail of the sampling distribution c. only in the lower tail of the sampling distribution d. only in the upper tail of the sampling distribution

in one tail of the sampling distribution

The rejection region for a one-tailed hypothesis test _____. a. has an area of 1 - ß b. has an area equal to the confidence coefficient c. is in the tail that supports the null hypothesis d. is in the tail that supports the alternative hypothesis

is in the tail that supports the alternative hypothesis

In a two-tailed hypothesis test, the null hypothesis should be rejected if the p-value is _____. a. less than or equal to a b. less than or equal to 2a c. greater than or equal to a d. greater than or equal to 2a

less than or equal to a

For a two-tailed hypothesis test about μ, we can use any of the following approaches EXCEPT compare the _____ to the _____. a. confidence interval estimate of μ; hypothesized value of μ b. p-value; value of α c. value of the test statistic; critical value d. level of significance; confidence coefficient

level of signifance; confidence coefficient

If the cost of a Type I error is high, a smaller value should be chosen for the _____. a. critical value b. confidence coefficient c. level of significance d. test statistic

level of significance

The level of significance is the _____. a. maximum allowable probability of a Type II error b. maximum allowable probability of a Type I error c. same as the confidence coefficient d. same as the p-value

maximum allowable probability of a type 1 error

If a hypothesis is rejected at a 5% level of significance, it _____. a. will always be rejected at the 1% level b. will always be accepted at the 1% level c. will never be tested at the 1% level d. may be rejected or not rejected at the 1% level

may be rejected or not rejected at the 1% level

Refer to Exhibit 9-3. If the test is done at a 5% level of significance, the null hypothesis should _____. a. not be rejected b. be rejected c. Not enough information is given to answer this question. d. None of the answers is correct.

not be rejected

Refer to Exhibit 9-5. If the test is done at a 2% level of significance, the null hypothesis should _____. a. not be rejected b. be rejected c. Not enough information is given to answer this question. d. None of the answers is correct.

not be rejected

Refer to Exhibit 9-4. At a .05 level of significance, it can be concluded that the mean age is _____. a. not significantly different from 24 b. significantly different from 24 c. significantly less than 24 d. significantly less than 25

not signifantly different from 24

Refer to Exhibit 9-6. At a .05 level of significance, it can be concluded that the proportion of the population in favor of candidate A is _____. a. significantly greater than 75% b. not significantly greater than 75% c. significantly greater than 80% d. not significantly greater than 80%

not significantly greater than 75%

The level of significance in hypothesis testing is the probability of _____. a. accepting a true null hypothesis b. accepting a false null hypothesis c. rejecting a true null hypothesis d. accepting a true null hypothesis, accepting a false null hypothesis, or rejecting a true null hypothesis, depending on the situation

rejecting a true null hypothesis

A two-tailed test is performed at a 5% level of significance. The p-value is determined to be .09. The null hypothesis _____. a. must be rejected b. should not be rejected c. may or may not be rejected, depending on the sample size d. has been designed incorrectly

should not be rejected

Refer to Exhibit 9-2. At a .05 level of significance, it can be concluded that the mean of the population is _____. a. significantly greater than 3 b. not significantly greater than 3 c. significantly less than 3 d. significantly greater than 3.18

significntly greater 3

More evidence against H0 is indicated by _____. a. lower levels of significance b. smaller p-values c. smaller critical values d. lower probabilities of a Type II error

smaller p-values

In hypothesis testing, if the null hypothesis has been rejected when the alternative hypothesis has been true, _____. a. a Type I error has been committed b. a Type II error has been committed c. either a Type I or Type II error has been committed d. the correct decision has been made

the correct decision has been made

In hypothesis testing if the null hypothesis is rejected, _____. a. no conclusions can be drawn from the test b. the alternative hypothesis must also be rejected c. the data must have been collected incorrectly d. the evidence supports the alternative hypothesis

the evidence supports the alternative hypothesis

In hypothesis testing, the alternative hypothesis is _____. a. the hypothesis tentatively assumed true in the hypothesis-testing procedure b. the hypothesis concluded to be true if the null hypothesis is rejected c. the maximum probability of a Type I error d. All of the answers are correct.

the hpothesis concluded to be true if the null hypothesis is rejected

In the hypothesis testing procedure, α is _____. a. the level of significance b. the critical value c. the confidence level d. 1 − level of significance

the level of significance

Which of the following does NOT need to be known in order to compute the p-value? a. knowledge of whether the test is one-tailed or two-tailed b. the value of the test statistic c. the level of significance d. All of the answers are correct.

the level of significance

In hypothesis testing, the hypothesis tentatively assumed to be true is _____. a. the alternative hypothesis b. the null hypothesis c. either the null or the alternative d. None of the answers is correct.

the null hpyothesis

If a hypothesis test has a Type I error probability of .05, that means if the null hypothesis is _____. a. false, it will not be rejected 5% of the time b. false, it will be rejected 5% of the time c. true, it will not be rejected 5% of the time d. true, it will be rejected 5% of the time

true, it will be rejected 5% of the time

Refer to Exhibit 9-1. The p-value is _____. a. .5107 b. .0214 c. .0107 d. 2.1

0.0107

Refer to Exhibit 9-5. The p-value is equal to _____. a. -.0166 b. .0166 c. .0332 d. .9834

0.0166

Refer to Exhibit 9-2. The p-value is _____. a. .025 b. .0456 c. .05 d. .0228

0.0228

Refer to Exhibit 9-6. The p-value is _____. a. .2112 b. .05 c. .025 d. .1251

0.1251

. Refer to Exhibit 9-3. The p-value is equal to _____. a. .1151 b. .3849 c. .2698 d. .2302

0.2302

For a two-tailed hypothesis test with a test statistic value of z = 2.05, the p-value is _____. a. .0101 b. .0202 c. .0404 d. .4899

0.404

Read the t statistic from the table of t distributions and circle the correct answer. A one-tailed test (lower tail), a sample size of 10 at a .10 level of significance; t = _____. a. 1.383 b. -1.372 c. -1.383 d. -2.821

-1.383

Read the z statistics from the normal distribution table and circle the correct answer. A two-tailed test at a .0694 level of significance; z = _____. a. -1.96 and 1.96 b. -1.48 and 1.48 c. -1.09 and 1.09 d. -.86 and .86

-1.48 and 1.48

Read the z statistic from the normal distribution table and circle the correct answer. A one-tailed test (lower tail) at a .063 level of significance; z = _____. a. -1.86 b. -1.53 c. -1.96 d. -1.645

-1.53

Refer to Exhibit 9-5. The test statistic equals _____. a. -2.131 b. -.53 c. .53 d. 2.131

-2.131

Excel's __________ function can be used to calculate a p-value for a hypothesis test. a. RAND b. NORM.S.DIST c. NORM.S.INV d. Not enough information is given to answer this question.

NORM.S.DIST

When using Excel to calculate a p-value for a lower-tail hypothesis test, which of the following must be used? a. RAND b. 1 − NORM.S.DIST c. NORM.S.DIST d. Not enough information is given to answer this question.

NORM.S.DIST

Which Excel function would NOT be appropriate to use when conducting a hypothesis test for a population proportion? a. NORM.S.DIST b. COUNTIF c. STDEV d. All of the answers are correct.

STDEV

A Type II error is committed when _____. a. a true alternative hypothesis is mistakenly rejected b. a true null hypothesis is mistakenly rejected c. the sample size has been too small d. not enough information has been available

a true alternative hypothesis is mistakenly rejected

If a hypothesis test leads to the rejection of the null hypothesis, a _____. a. Type II error must have been committed b. Type II error may have been committed c. Type I error must have been committed d. Type I error may have been committed

Type 1 error must have neem committed

The level of significance is symbolized by _____. a. a b. ß c. σ d. p

a

The probability of making a Type I error is denoted by _____. a. α b. β c. 1 − α d. 1 − β

a

In hypothesis testing, the critical value is _____. a. a number that establishes the boundary of the rejection region b. the probability of a Type I error c. the probability of a Type II error d. the same as the p-value

a number that establishes the boundary of the rejection region

Two approaches to drawing a conclusion in a hypothesis test are _____. a. p-value and critical value b. one-tailed and two-tailed c. Type I and Type II d. null and alternative

one-tailed and two-tailed

A p-value is the _____. a. probability, when the null hypothesis is true, of obtaining a sample result that is at least as unlikely as what is observed b. value of the test statistic c. probability of a Type II error d. probability corresponding to the critical value(s) in a hypothesis test

probability, when the null hypothesis is true, of obtaining a sample result that is at least as unlikely as what is observed

For a sample size of 30, changing from using the standard normal distribution to using the t distribution in a hypothesis test _____. a. will result in the rejection region being smaller b. will result in the rejection region being larger c. would have no effect on the rejection region d. Not enough information is given to answer this question.

will result in the rejection region being smaller