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71.Exhibit 9-4.

A school teacher is worried that the concentration of dangerous, cancer-causing radon gas in her classroom is greater than the safe level of 4pCi/L. The school samples the air for 36 days and finds an average concentration of 4.4pCi/L with a standard deviation of 1pCi/L.

Refer to Exhibit 9-4. In order to test whether the average level of radon gas is greater than the safe level, the appropriate hypotheses are ____________.

A.

B.

C.

D.

72.Exhibit 9-4.

A school teacher is worried that the concentration of dangerous, cancer-causing radon gas in her classroom is greater than the safe level of 4pCi/L. The school samples the air for 36 days and finds an average concentration of 4.4pCi/L with a standard deviation of 1pCi/L.

Refer to Exhibit 9-4. The value of the test statistic is ___________.

A.

B.

C.

D.

73.Exhibit 9-4.

A school teacher is worried that the concentration of dangerous, cancer-causing radon gas in her classroom is greater than the safe level of 4pCi/L. The school samples the air for 36 days and finds an average concentration of 4.4pCi/L with a standard deviation of 1pCi/L.

Refer to Exhibit 9-4. At a 5% significance level, the critical value(s) is(are) _______.

A.

B.

C.

D.

74.Exhibit 9-4.

A school teacher is worried that the concentration of dangerous, cancer-causing radon gas in her classroom is greater than the safe level of 4pCi/L. The school samples the air for 36 days and finds an average concentration of 4.4pCi/L with a standard deviation of 1pCi/L.

Refer to Exhibit 9-4. At a 5% significance level, the decision is to ___________.

A. reject we can conclude that the mean concentration of radon gas is greater than the safe level

B. reject we cannot conclude that the mean concentration of radon gas is greater than the safe level

C. do not reject we can conclude that the mean concentration of radon gas is greater than the safe level

D. do not reject we cannot conclude that the mean concentration of radon gas is greater than the safe level

75.A car dealer who sells only late-model luxury cars recently hired a new salesman and believes that this salesman is selling at lower markups. He knows that the long-run average markup in his lot is \$5,600. He takes a random sample of 16 of the new salesman's sales and finds an average markup of \$5,000 and a standard deviation of \$800. Assume the markups are normally distributed. What is the value of an appropriate test statistic for the car dealer to use to test his claim?

A.

B.

C.

D.

76.A temp agency feels that one of its recruiters has unorthodox methods and claims that the wages the recruiter secures for its temps differs from the agency's average wage of \$12 per hour. The agency takes a random sample of 49 recent contracts the recruiter secured and finds an average wage of \$11.25 per hour and a standard deviation of \$2.25 per hour. Does the evidence support the agency's claim at the 5% significance level?

A. Yes, since the p-value is greater than the claim is supported.

B. No, since the p-value is not greater than the claim is not supported.

C. Yes, since the value of the test statistic is less than the critical value, the claim is supported.

D. No, since the value of the test statistic is greater than the critical value, the claim is not supported.

77.A newly hired basketball coach promised a high-paced attack that will put more points on the board than the team's previously tepid offense historically managed. After a few months, the team owner looks at the data to test the coach's claim. He takes a sample of 36 of the team's games under the new coach and finds that they scored an average of 101 points with a standard deviation of 6 points. Over the past 10 years, the team had averaged 99 points. What is(are) the appropriate critical value(s) to test the new coach's claim at the 1% significance level?

A. -2.438

B. -2.438 and 2.438

C. 2.326

D. 2.438

78.A newly hired basketball coach promised a high-paced attack that will put more points on the board than the team's previously tepid offense historically managed. After a few months, the team owner looks at the data to test the coach's claim. He takes a sample of 36 of the team's games under the new coach and finds that they scored an average of 101 points with a standard deviation of 6 points. Over the past 10 years, the team had averaged 99 points. What is the value of the appropriate test statistic to test the new coach's claim at the 1% significance level?

A.

B.

C.

D.

79.What type of data would necessitate using a hypothesis test of the population proportion rather than a test of the population mean?

A. Ratio

B. Interval

C. Qualitative

D. Quantitative

80.You want to test if more than 20% of homes in a neighborhood have recently been sold through a short sale, at a foreclosure auction, or by the bank following an unsuccessful foreclosure auction. You take a sample of 60 homes from this neighborhood and find that 14 fit your criteria. The appropriate null and alternative hypotheses are ___________.

A.

B.

C.

D.

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