Question

A girl scout troop sold cookies to raise funds. Each troop member recorded the number of boxes she sold. The number of boxes she sold. The number of boxes sold was normally distributed with a mean of 22 boxes sold and a standard deviation of 4 boxes. In order to help determine how many boxes ould be sold the next year, the troop leader decided to focus on the range made from the bottom 30% to the top 20%. Find the number of boxes that represent the desired range values.

Answer 1

A suitable probability calculator tells you the 30th percentile corresponds to 19.9 boxes, and the 80th percentile corresponds to 25.4 boxes.

The desired range of values is from about 19.9 to 25.4 boxes. These numbers can be rounded to 20–25.