9.
Right-tailed, population mean is being tested.
10.
Left-tailed, population proportion is being tested.
11.
Two-tailed, population standard deviation is being tested.
12.
Right-tailed, population proportion is being tested.
13.
Left-tailed, population mean is being tested.
14.
Two-tailed, population standard deviation is being tested.
15.
Ho: p = .399
H1: p > .399 Type I error: This is made if the sample evidence leads the president to believe that p > .399 when, in fact, the proportion of students who enrolled at Joliet Junior College who earn a bachelor’s degree within 6 years is not more than .399. Type II Error: This is made if the president does not reject the null hypothesis that the proportion of students who earn a bachelor’s degree within 6 years is .399 when, in fact, the proportion of students enrolled at Joliet Junior College who earn a bachelor’s degree within 6 years is more than .399.
17.
Ho: u = 245,700
H1: u < 245,700 Type I error: This is made if the sample evidence leads the real estate broker to believe that u < 245,700 when, in fact, the mean price of a single-family home in her neighborhood is not less than $245,700. Type II error: This is made if the real estate broker does not reject the null hypothesis that the mean price of a single family home is $245,700 when, in fact, the mean price of a single family home in her neighborhood is less than $245,700.
19.
Ho: standard deviation = 0.7
H1: standard deviation < 0.7 Type I error: This is made if the sample evidence leads the quality-control manager to believe that standard deviation < 0.7 when, in fact, the standard deviation required to open a certain valve is not less than 0.7. Type II error: This is made if the quality-control manager does not reject the null hypothesis that the standard deviation required to open a certain valve is 0.7 psi when, in fact, the standard deviation is less than 0.7.
21.
Ho: u = 48.79
H1: u does not equal 48.79 Type I error: This is made if the sample evidence leads the researcher to believe that u does not equal 48.79 when, in fact, the mean monthly revenue for a cell phone is equal to $48.79. Type II error: This is made if the researcher does not reject the null hypothesis that the mean monthly revenue for a cell phone is $48.79 when, in fact, is is not $48.79.
7.
9.
11.
13.
The p-value represents the probability of achieving greater than 0.5 companies which were considered winners. In other words, it is the likelihood of the dart-picking strategy producing companies that were considered winners more than 0.5.In this case, 27.43% of the time the dart-picking strategy picks more than half the companies that are considered winners.
15. Note this is slightly modified version of the book problem Just answer a) b) and c) fromt the skeleton.
p = 0.47.
Ho: p = 0.5
H1: p < 0.5
17.
The test statistic = 0.022, and the P-value is .2578
Since the P-value is greater than the level of significance, a = 0.01, we do not reject the null hypothesis and cannot find enough evidence to say that no more than 1.9% of Lipitor patients experience flulike symptoms.
19.
The test statistic = 0.49, and the P-value is .0027
Since the P-value is less than the level of significance, a = 0.05, we reject the null hypothesis and find enough evidence to say that Hawaii has a higher percentage of people with positive BAC.