In 2006, Merck released a vaccine named Gardasil for HPV

(a): Give a 98% confidence interval for the differences in the proportion of young women who develop cervical cancer with and without the vaccine.

Lower confidence level: 

Upper confidence level: 

(b): Give a 98% confidence interval for the differences in the proportion of young women who develop genital warts with and without the vaccine.

Lower confidence level: 

Upper confidence level: 

2. Here is data on the age (in months) that 20 children said their first words of English.

If you treat this as an SRS, does it provide evidence at significance level 4% that the mean age at first word is greater than 12 months?

(a): Give the associated P-value.

P-value:: 

3. 

Here is data on the age (in months) that 20 children said their first words of English.

Treat this as an SRS. Use it to provide a 90% confidence interval of the mean age in months at which children say their first words.

Lower confidence level: 

Upper confidence level: 

4. Fabrics respond differently to the same dye. Clothing manufacturers need to be able to match the colors of different fabrics. A researcher dyed samples of cotton and of ramie with a dye called procion blue, applied in the same way to each sample. Then she measured the lightness of the color with a colorimeter on a scale in which black is 0, white is 100. Here are the data for 8 pieces of each fabric.

Do these samples provide evidence significant at the 1% level that the dye affects the cotton and ramie fabrics differently?

Formulate H0 and Ha.

a. Give the test statistic: 

b. Give the P-value: 

c. Your decision for the hypothesis test:   A. Reject Ha.   B. Reject H0.   C. Do Not Reject H0.   D. Do Not Reject Ha.

5. Fabrics respond differently to the same dye. Clothing manufacturers need to be able to match the colors of different fabrics. A researcher dyed samples of cotton and of ramie with a dye called procion blue, applied in the same way to each sample. Then she measured the lightness of the color with a colorimeter on a scale in which black is 0, white is 100. Here are the data for 8 pieces of each fabric.

Evidently one procedure gives darker colors than the other. Make a confidence interval estimate for the mean darkness of cotton minus the mean darkness of ramie after this dye procedure. Use 99% as your confidence level.

Lower Confidence Level: 

Upper Confidence Level: 

6. A psychology professor asked her sophomore students "Does either of your parents allow you to drink alcohol around him or her?" and when drinking (not necessarily around your parent) "How many drinks do you typically have per session?" (For these purposes, a drink is defined as a 12 oz. beer, a 4oz. glass of wine, or a one oz. shot of liquor.)

The next tables contains the responses from female students who are not abstainers.

Drinks per session for students whose parent allows them to drink 

Drinks per session for students whose parents do not allow them to drink 

If you treat these two samples as SRSs, do they provide significant evidence at the 3% level that the behavior of the parents affects how many drinks the students have on average?

Formulate H0 and Ha.

a. Give the test statistic: 

b. Give the P-value: 

c. Your decision for the hypothesis test:   A. Reject Ha.   B. Reject H0.   C. Do Not Reject Ha.   D. Do Not Reject H0.

7. A psychology professor asked her sophomore students "Does either of your parents allow you to drink alcohol around him or her?" and when drinking (not necessarily around your parent) "How many drinks do you typically have per session?" (For these purposes, a drink is defined as a 12 oz. beer, a 4oz. glass of wine, or a one oz. shot of liquor.)

The next tables contains the responses from female students who are not abstainers.

Drinks per session for students whose parent allows them to drink 

Drinks per session for students whose parents do not allow them to drink 

If you treat these students as an SRS, construct a 99% confidence interval for the population proportion of sophomore college students at least one of whose parents allows them to drink around him or her. Do both the large sample and the plus four procedure.

Large Sample:  Lower confidence level:   Upper confidence level: 

Plus four method:  Lower confidence level:   Upper confidence level: 

8. Two different protocols for treating breast cancer were compared. One, called ALND, involves more radical surgery (more tissue is removed) with a greater risk of side effects. The other, called SLND, involves less tissue removal and possibly fewer side effects. (There is more detail about this study on p. 526 of Moore, Notz and Fligner, 6th Edition.)

A group of patients is randomly assigned to one or the other treatment and the patients are followed up after five years to see if they are still disease free at that point. The results are summarized in the following table.

Do this study provide evidence significant at the 10% level that the proportions of patients who are cancer free after five years are different under the two treatments?

Formulate H0 and Ha.

a. Give the test statistic: 

b. Give the P-value: 

c. Your decision for the hypothesis test:   A. Do Not Reject H0.   B. Reject Ha.   C. Do Not Reject Ha.   D. Reject H0.

9. You construct a confidence interval of the form0.29493≤p≤0.45978

from a sample of size 102 with 38 successes using the "plus 4" procedure.

Give the confidence level.

Confidence level:  %