A normal population has mean Mu 7 and standard deviation si

A normal population has mean Mu = 7 and standard deviation sigma = 5. Part 1 What proportion of the population is less than 19? The proportion of the population less than 19 is Part 2 What is the probability that a randomly chosen value will be greater than 4? The probability that a randomly chosen value will be greater than 4 is

Solution

P(X < 19) = P(Z < (19-7)/5 )

= P(Z < 2.4)

= 0.9918

P(X > 4) = P(Z > (4-7)/5 )

= P(Z > -0.6)

= 0.7257

Note: The probability values are obtained from standard normal table.