Question

Let X be a normal random variable with mean 40 and standard deviation 2. Find P(X < 28).

Answer 1

0

Explanation:

Given :

Mean = 40 ; Standard deviation = 2

P(x < 28)

Obtain the Zscore :

Z = (x - mean) / standard deviation

P(Z < (28 - 40) / 2))

Z = (28 - 40) / 2

Z = - 12 / 2

Z = - 6

P(Z < - 6) = 0.000000