Question

Sample score normally distributed mean =27 variance 16 What is the probability of a score less than 34?

Answer 1

Data given:
Mean = 27

, SD === 4

, P(Y < 34) = ?;

P(Y < 34) = P(Y - mean < 34 - mean)
                  = P( (Y - mean)/SD < (34 - mean)/SD
                  = P(Z < (34 - mean)/SD)
                  = P(Z < (34 - 27)/4)
                  = P(Z < 1.75)
                  = 0.9601--------------from standard normal table.