BMI values The ideal BMI for a female is between 18.5 and 24.9.

A year ago, a group of female friends had an average BMI of 25.4, and 54% of them exceeded the ideal maximum BMI of 24.9.

a) If a Normal model is appropriate, what was the standard deviation of the BMI values of the females a year ago?

b) The females who had an overweight BMI last year decided to go on a diet. This year, the group has an average BMI of 23.5 and only 28% of them exceed the ideal maximum BMI.

What is this year’s standard deviation for the appropriate Normal model?

c) Which BMI values are more consistent, last year’s or this year’s? Explain.