Based on a survey conducted by Greenfield Online, 25- to 34-year-olds spend the most each week on fast food. The average weekly amount of $44 (based on 115 respondents) was reported in a May 2009 USA Today Snapshot. Assuming that weekly fast food expenditures are normally distributed with a known standard deviation of $14.50, construct a 90% confidence interval for the mean weekly amount that 25- to 34-year-olds spend each week on fast food.