In 1851 there were 25,466 nurses in Great Britain.

Age Range Yrs 20-29 30-39 40-49 50-59 60-69 70-79 80-89

Midpoint X 24.5 34.5 44.5 54.5 64.5 74.5 84.5

Percent of Nurses 5.7 9.7 19.5 29.2 25.0 9.1 1.8

I have three parts to this question that is similar to one I am working on, Please detail how you do this:

1) Find the probability that a British nurse selected at random in 1851 would be 60 years or older. (My guess is The sum of the percent of nurses 60 years are older are added equaling 36% or 1967.76/25466) am I even close?

2) Compute he expected age µ of a British nurse contemporary.

3) Compute the standard deviation α for the ages of the nurses shown.