find Pr[X=66.86]

Question

Given a normal random variable X with the mean 62 and a standard deviation 3,  find Pr[X≤66.86]

Answer 1

Heather,

 

First find the number of standard deviations:

(66.86-62)/3=1.62

 

Then find the percentage for a value 1.62 std deviations above the average:

normsdist(1.62,1)=.9474 (Using Excel)

 

Hope that helps,

Deanna