Interval Estimator

#1
After conducting
research she learns that the national average spending by women on skin cleansing
products is $94.40 annually. In other words, she will assume the average spending in
her town is the same as the national average unless she has strong evidence that says
otherwise. SDM gives Lisa a random sample of the spending on skin cleansers by
50 women based on records from their spending using the “Optimum” card. The data is
in the file Assignment #2 data.xls, on the “Cleansers” tab.

This is what was asked: 2. Amanda also would like to include in her Business Plan an estimate for the average
amount women in her area do spend. Estimate with 95% confidence the average
amount of spending on fragrance products every 3 months.


I know how to do interval estimates pretty well. I am just confused on how I am supposed to get a result of 3 months spending. The data is annual. Do I just brake the amount I got into quarters.