13.2

The mean number of eggs per person eaten in the United States is 240. Do college students eat more eggs than the average American? The 52 college students surveyed averaged 260 eggs per person and their standard deviation was 75. What can be concluded at the = 0.01 level of significance?

1. For this study, we should use Select an answer
3. z-test for a population proportion
5. t-test for a population mean
7. The null and alternative hypotheses would be:

H0:H0: ?

p

Select an answer

<

=

>

H1:H1: ?

p

Select an answer

=

<

>

1. The test statistic ?
3. t
5. z
6. = (please show your answer to 3 decimal places.)
7. The p-value = (Please show your answer to 4 decimal places.)
8. The p-value is ?
12. >
14. Based on this, we should Select an answer
16. reject
18. accept
20. fail to reject
21. the null hypothesis.
22. Thus, the final conclusion is that ...

• The data suggest that the population mean is notsignificantlymore than 240 at = 0.01, so there is statistically insignificant evidence to conclude that the population mean number of eggs consumed by college students per year is more than 240.
• The data suggest that the sample mean is notsignificantlymore than 240 at = 0.01, so there is statistically insignificant evidence to conclude that the sample mean number of eggs consumed by college students per year is more than 260.
• The data suggest that the populaton mean issignificantlymore than 240 at = 0.01, so there is statistically significant evidence to conclude that the population mean number of eggs consumed by college students per year is more than 240.

1. Interpret the p-value in the context of the study.

• There is a 3.00386646% chance of a Type I error.
• If the population mean number of eggs consumed by college students per year is 240 and if another 52 students are surveyed then there would be a 3.00386646% chance that the population mean number of eggs consumed by college students per year would be greater than 240.
• If the population mean number of eggs consumed by college students per year is 240 and if another 52 college students are surveyed then there would be a 3.00386646% chance that the sample mean for these 52 students surveyed would be greater than 260.
• There is a 3.00386646% chance that the population mean number of eggs consumed by college students per year is greater than 240 .

1. Interpret the level of significance in the context of the study.

• If the population mean number of eggs consumed by college students per year is 240 and if another 52 college students are surveyed then there would be a 1% chance that we would end up falsely concluding that the population mean number of eggs consumed by college students per year is more than 240.
• There is a 1% chance that you will find the chicken that lays the golden eggs.
• There is a 1% chance that the population mean number of eggs consumed by college students per year is more than 240.
• If the population population mean number of eggs consumed by college students per year is more than 240 and if another 52 college students are surveyed then there would be a 1% chance that we would end up falsely concluding that the population mean number of eggs consumed by college students per year is equal to 240.

13.2

It takes an average of 14 minutes for blood to begin clotting after an injury. An EMT wants to see if the average will decline if the patient is immediately told the truth about the injury. The EMT randomly selected 45 injured patients to immediately tell the truth about the injury and noticed that they averaged 12.3 minutes for their blood to begin clotting after their injury. Their standard deviation was 4.2 minutes. What can be concluded at the the = 0.05 level of significance?

1. For this study, we should use Select an answer
3. z-test for a population proportion
5. t-test for a population mean
7. The null and alternative hypotheses would be:

H0:H0: ?

p

Select an answer

>

<

=

H1:H1: ?

p

Select an answer

<

=

>

1. The test statistic ?
3. t
5. z
6. = (please show your answer to 3 decimal places.)
7. The p-value = (Please show your answer to 4 decimal places.)
8. The p-value is ?
12. >
14. Based on this, we should Select an answer
16. accept
18. reject
20. fail to reject
21. the null hypothesis.
22. Thus, the final conclusion is that ...

• The data suggest the population mean is notsignificantlyless than 14 at = 0.05, so there is statistically significant evidence to conclude that the population mean time for blood to begin clotting after an injury if the patient is told the truth immediately is equal to 14.
• The data suggest that the population mean is notsignificantlyless than 14 at = 0.05, so there is statistically insignificant evidence to conclude that the population mean time for blood to begin clotting after an injury if the patient is told the truth immediately is less than 14.
• The data suggest the populaton mean issignificantlyless than 14 at = 0.05, so there is statistically significant evidence to conclude that the population mean time for blood to begin clotting after an injury if the patient is told the truth immediately is less than 14.

13.3

Nationally, patients who go to the emergency room wait an average of 6 hours to be admitted into the hospital. Do patients at rural hospitals have a lower waiting time? The 15 randomly selected patients who went to the emergency room at rural hospitals waited an average of 5.7 hours to be admitted into the hospital. The standard deviation for these 15 patients was 1.2 hours. What can be concluded at the the = 0.10 level of significance level of significance?

1. For this study, we should use Select an answer
3. z-test for a population proportion
5. t-test for a population mean
7. The null and alternative hypotheses would be:

H0:H0: ?

p

Select an answer

>

=

<

H1:H1: ?

p

Select an answer

=

<

>

1. The test statistic ?
3. t
5. z
6. = (please show your answer to 3 decimal places.)
7. The p-value = (Please show your answer to 4 decimal places.)
8. The p-value is ?
10. >
14. Based on this, we should Select an answer
16. reject
18. fail to reject
20. accept
21. the null hypothesis.
22. Thus, the final conclusion is that ...

• The data suggest the populaton mean issignificantlylower than 6 at = 0.10, so there is statistically significant evidence to conclude that the population mean waiting time to be admitted into the hospital from the emergency room for patients at rural hospitals is lower than 6 hours.
• The data suggest the population mean is notsignificantlylower than 6 at = 0.10, so there is statistically insignificant evidence to conclude that the population mean waiting time to be admitted into the hospital from the emergency room for patients at rural hospitals is equal to 6 hours.
• The data suggest that the population mean awaiting time to be admitted into the hospital from the emergency room for patients at rural hospitals is notsignificantlylower than 6 hours at = 0.10, so there is statistically insignificant evidence to conclude that the population mean waiting time to be admitted into the hospital from the emergency room for patients at rural hospitals is lower than 6 hours.

13.4

The average number of cavities that thirty-year-old Americans have had in their lifetimes is 5. Do twenty-year-olds have a different number of cavities? The data show the results of a survey of 12 twenty-year-olds who were asked how many cavities they have had. Assume that the distribution of the population is normal.

7, 5, 5, 4, 6, 6, 6, 4, 4, 5, 4, 7

What can be concluded at the = 0.01 level of significance?

1. For this study, we should use Select an answer
3. z-test for a population proportion
5. t-test for a population mean
7. The null and alternative hypotheses would be:

H0:H0: ?

p

Select an answer

<

=

>

H1:H1: ?

p

Select an answer

<

=

>

1. The test statistic ?
3. t
5. z
6. = (please show your answer to 3 decimal places.)
7. The p-value = (Please show your answer to 4 decimal places.)
8. The p-value is ?
10. >
14. Based on this, we should Select an answer
16. fail to reject
18. accept
20. reject
21. the null hypothesis.
22. Thus, the final conclusion is that ...

• The data suggest the population mean is notsignificantlydifferent from 5 at = 0.01, so there is sufficient evidence to conclude that the population mean number of cavities for twenty-year-olds is equal to 5.
• The data suggest that the population mean number of cavities for twenty-year-olds is notsignificantlydifferent from 5 at = 0.01, so there is insufficient evidence to conclude that the population mean number of cavities for twenty-year-olds is different from 5.
• The data suggest the populaton mean issignificantlydifferent from 5 at = 0.01, so there is sufficient evidence to conclude that the population mean number of cavities for twenty-year-olds is different from 5.

1. Interpret the p-value in the context of the study.

• If the population mean number of cavities for twenty-year-olds is 5 and if you survey another 12 twenty-year-olds, then there would be a 46.27244948% chance that the sample mean for these 12 twenty-year-olds would either be less than 4.75 or greater than 5.
• There is a 46.27244948% chance that the population mean number of cavities for twenty-year-olds is not equal to 5.
• There is a 46.27244948% chance of a Type I error.
• If the population mean number of cavities for twenty-year-olds is 5 and if you survey another 12 twenty-year-olds then there would be a 46.27244948% chance that the population mean would either be less than 4.75 or greater than 5.

1. Interpret the level of significance in the context of the study.

• If the population mean number of cavities for twenty-year-olds is different from 5 and if you survey another 12 twenty-year-olds, then there would be a 1% chance that we would end up falsely concuding that the population mean number of cavities for twenty-year-olds is equal to 5.
• If the population mean number of cavities for twenty-year-olds is 5 and if you survey another 12 twenty-year-olds, then there would be a 1% chance that we would end up falsely concuding that the population mean number of cavities for twenty-year-olds is different from 5.
• There is a 1% chance that the population mean number of cavities for twenty-year-olds is different from 5.
• There is a 1% chance that flossing will take care of the problem, so this study is not necessary.