The mean amount of money spent on lunch per week for a sampl

The mean amount of money spent on lunch per week for a sample of 362 teenagers is dollar 34. If the margin of error for the population mean with a 98% confidence interval is 1.70. construct a 987% confidence interval for the mean amount of money spent on lunch per week for all teenagers.

Solution

We are given that,

mean amount of money spent on lunch per week (Xbar) = $34

sample size (n) = 362

margin of error (E) = 1.70

The 98% confidence interval for the mean is,

Xbar - E < mu < Xbar + E

lower endpoint = Xbar - E = 34 - 1.70 = 32.3

upper endpoint = Xbar + E = 34 + 1.70 = 35.7

The 98% confidence interval for the mean amount of money spent on lunch per week for all teenagers is (32.3, 35.7).