Statistics distribution

Question

A distribution of values is normal with a mean of 1310.6 and a standard deviation of 40.2

find the probability that a randomly selected value is less than 1397

Answer 1

let x = value

want to find P(x < 1397)

compute z = (1397 - 1301.6)/40.2 = 2.37

P(x < 1397) = P(z < 2.37) = 0.9911.