Chapter 9 Hypothesis Tests for One Population

4 The value obtained for the teststatistic, z, in aone-mean z-test is given. Whether the test is twotailed, lefttailed, or right tailed is also specified. For parts(a) and(b), determine theP-value and decidewhether, at the 10% significancelevel, the data provide sufficient evidence to reject the null hypothesis in favor of the alternative hypothesis.

a. The test statistic in aright-tailed test is z=0.65.

TheP-value is

( ? ) (Round to three decimal places asneeded.)

5 The value obtained for the teststatistic, z, in aone-mean z-test is given. Whether the test is twotailed, lefttailed, or right tailed is also specified. For parts(a) and(b), determine theP-value and decidewhether, at the 1% significancelevel, the data provide sufficient evidence to reject the null hypothesis in favor of the alternative hypothesis.

a. The test statistic in aleft-tailed test is z=2.08.

TheP-value is ( ? ) (Round to three decimal places asneeded.)

11 For atwo-tailed hypothesis test at the significance level , the null hypothesis H0: =0 will be rejected in favor of the alternative hypothesis Ha: 0 if and only if 0 lies outside the (1)-level confidence interval for . Illustrate the preceding relationship by obtaining the appropriateone-mean t-interval for the summary statistics provided. Complete parts(a) and(b).

a. According to asurvey, the average person watched 4.49 hours of television per day in 2005. A random sample of 20 people were asked for the number of hours of television watched per day for last year. At the 5% significancelevel, the data donotprovide sufficient evidence to conclude that the amount of television watched per day last year by the average person differed from that in 2005.(Note: x=4.709 hours and s=2.258 hours.)

The confidence interval is ( ? ) (Round to three decimal places asneeded.)

Suppose a guide book gives a certain car a retail value of $18,000. The table below shows askingprices, indollars, for a sample of the same car model and year. At the 10% significancelevel, do the data provide sufficient evidence to conclude that the mean asking price of the car is less than the listed retailvalue?

16,520

16,001

16,097

15,937

15,782

15,643

14,505

13,596

15,671

15,683

Set up the hypotheses for the Wilcoxonsigned-rank test.

H0: ( ? )

Ha: ( ? )