10.15 Exercises  (Page 8/8)

The alternate hypothesis is

• A
• B
• C $p\ge 0\text{.}\text{30}$
• D $p>0\text{.}\text{30}$

After conducting the test, your decision and conclusion are

• A Reject $H_o$ : There is sufficient evidence to conclude that more than 30% of teen girls smoke to stay thin.
• B Do not reject $H_o$ : There is not sufficient evidence to conclude that less than 30% of teen girls smoke to stay thin.
• C Do not reject $H_o$ : There is not sufficient evidence to conclude that more than 30% of teen girls smoke to stay thin.
• D Reject $H_o$ : There is sufficient evidence to conclude that less than 30% of teen girls smoke to stay thin.

An appropriate alternative hypothesis is

• A $p=0\text{.}\text{20}$
• B $p>0\text{.}\text{20}$
• C
• D

At a 1% level of significance, an appropriate conclusion is:

• A There is insufficient evidence to conclude that the percent of EVC students that attended the midnight showing of Harry Potter is less than 20%.
• B There is sufficient evidence to conclude that the percent of EVC students that attended the midnight showing of Harry Potter is more than 20%.
• C There is sufficient evidence to conclude that the percent of EVC students that attended the midnight showing of Harry Potter is less than 20%.
• D There is insufficient evidence to conclude that the percent of EVC students that attended the midnight showing of Harry Potter is at least 20%.

The Type I error is to conclude that the percent of EVC students who attended is

• A at least 20%, when in fact, it is less than 20%.
• B 20%, when in fact, it is 20%.
• C less than 20%, when in fact, it is at least 20%.
• D less than 20%, when in fact, it is less than 20%.

The distribution to be used for this test is $\overline{X}$ ~

• A $N(7\text{.}\text{24},\frac{1\text{.}\text{93}}{\sqrt{\text{22}}})$
• B $N(7\text{.}\text{24},1\text{.}\text{93})$
• C $t_{\text{22}}$
• D $t_{\text{21}}$

The Type II error is to not reject that the mean number of hours of sleep LTCC students get per night is at least 7 when, in fact, the mean number of hours

• A is more than 7 hours.
• B is at most 7 hours.
• C is at least 7 hours.
• D is less than 7 hours.

The null and alternate hypotheses are:

• A $H_o:\overline{x}=4\text{.}5$ , $H_a:\overline{x}>4\text{.}5$
• B $H_o:\mu \ge 4\text{.}5$
• C $H_o:\mu =4\text{.}\text{75}$ $H_{a:}\mu >4\text{.}\text{75}$
• D $H_o:\mu =4\text{.}5$ $H_a:\mu >4\text{.}5$

At a significance level of $a=0\text{.}\text{05}$ , what is the correct conclusion?

• A There is enough evidence to conclude that the mean number of hours is more than 4.75
• B There is enough evidence to conclude that the mean number of hours is more than 4.5
• C There is not enough evidence to conclude that the mean number of hours is more than 4.5
• D There is not enough evidence to conclude that the mean number of hours is more than 4.75

The Type I error is:

• A To conclude that the current mean hours per week is higher than 4.5, when in fact, it is higher.
• B To conclude that the current mean hours per week is higher than 4.5, when in fact, it is the same.
• C To conclude that the mean hours per week currently is 4.5, when in fact, it is higher.
• D To conclude that the mean hours per week currently is no higher than 4.5, when in fact, it is not higher.