9.1 Homework (modified r. bloom)  (Page 5/5)

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 $H_o$ : More than 30% of teen girls smoke to stay thin.

• B

  Do not reject $H_o$ : Less than 30% of teen girls smoke to stay thin.

• C

  Do not reject $H_o$ : At most 30% of teen girls smoke to stay thin.

• D

  Reject $H_o$ : 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

  The percent of EVC students who attended the midnight showing of Harry Potter is at least 20%.

• B

  The percent of EVC students who attended the midnight showing of Harry Potter is more than 20%.

• C

  The percent of EVC students who attended the midnight showing of Harry Potter is less than 20%.

• D

  There is not enough information to make a decision.

The Type I error is believing 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 “I believe that the average number of hours of sleep LTCC students get per night

• A

  is less than 7 hours when, in fact, it is at least 7 hours.”

• B

  is less than 7 hours when, in fact, it is less than 7 hours.”

• C

  is at least 7 hours when, in fact, it is at least 7 hours.”

• D

  is at least 7 hours when, in fact, it 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 $a=0\text{.}\text{05}$ , the correct conclusion is:

• A

  The average in 2007 is higher than it was in 1995.

• B

  The average in 1995 is higher than in 2007.

• C

  The average is still about the same as it was in 1995.

• D

  The test is inconclusive.

The Type I error is:

• A

  To conclude the average hours per week in 2007 is higher than in 1995, when in fact, it is higher.

• B

  To conclude the average hours per week in 2007 is higher than in 1995, when in fact, it is the same.

• C

  To conclude the average hours per week in 2007 is the same as in 1995, when in fact, it is higher.

• D

  To conclude the average hours per week in 2007 is no higher than in 1995, when in fact, it is not higher.