The 2014-15 Consumer Expenditure Survey for the Baltimore Metropolitan area provided information on average annual expenditures. Use a sample size of 100 for each of the following problems.

a. Mean spent on food at home = $4,502. Assume that the population standard deviation equals $700.

(1) Compute a 95% confidence interval and calculate the confidence interval width.

(2) Compute a 99% confidence interval and calculate the confidence interval width.

b. Mean spent on food away from home = $3,278. Assume that the population standard deviation equals $650.

(1) Compute a 95% confidence interval and calculate the confidence interval width.

(2) Compute a 99% confidence interval and calculate the confidence interval width.

c. Mean spent on entertainment = $2,790. Assume that the population standard deviation equals $500.

(1) Compute a 95% confidence interval and calculate the confidence interval width.
(2) Compute a 99% confidence interval and calculate the confidence interval width.
d. Mean spent on tobacco products and smoking supplies = $328. Assume that the population standard deviation equals $100.
(1) Compute a 95% confidence interval and calculate the confidence interval width.

(2) Compute a 99% confidence interval and calculate the confidence interval width.

e. Look at the results of a-d and present a summary statement regarding the relationship between the 95% confidence interval and 99% confidence interval for the same set of data.