(solution) A random variable, X, has a normal distribution with a mean of 50

(solution) A random variable, X, has a normal distribution with a mean of 50

A random variable, X, has a normal distribution with a mean of 50 and unknown standard deviation. The probability that X exceeds 70 is 0.12. Find the probability that X lies between 30 and 70.You can solve this problem with or without a Standard Normal Table

A)

0.88

B)

0.06

C)

0.44

D)

0.95

E)

0.76
Given:
Question:
A random variable, X, has a normal distribution with a mean of 50 and unknown standard deviation. The
probability that X exceeds 70 is 0.12. Find the probability that X lies…