Reference no: EM131729561

Question: Refer to Exercise. In the sample, there were 4594 individuals with at least a college degree and n = 7076 individuals with at least a high school diploma (but not a college degree). Following is Minitab output with a 95% confidence interval for the difference in proportions experiencing episodic tension-type headaches in the two educational groups:

a. Write two or three sentences that interpret the results.

b. Provide the formula that is used to calculate the interval, and substitute appropriate numerical values into the formula.

Exercise: In a study done in Maryland, investigators surveyed individuals by telephone about how often they get tension headaches (Schwartz et al., 1998). One response variable that was measured was whether or not the respondent had experienced an episodic tension-type headache (ETTH) in the prior year. A headache pattern was called "episodic" if the headaches occurred less often than 15 times a month; otherwise, the headaches were called "chronic." Of the 1600 women in the survey aged 18 to 29, a total of 653 said that they had experienced ETTHs in the last year. Of the 2122 women in the 30- to 39-year-old age group, the number having experienced episodic headaches was 995.

a. Calculate the proportion in each group who experienced an episodic headache in the prior year, and compute the difference in these two proportions.

b. Compute a 95% confidence interval for the difference between the proportions for these age groups in the population. Write a sentence that interprets this confidence interval.