Question

Assume the random variable X is normally distributed with mean μ = 50 and standard deviation σ= 7. Compute the probability.

Answer 1

Complete question is;

Assume the random variable X is normally distributed with mean μ = 50 and standard deviation σ = 7. What is the probability P (X > 42)?

Answer:

P(X > 42) = 0.1271

Explanation:

We are given;

mean; μ = 50

Standard deviation; σ = 7

Formula for the z-score is;

z = (x - μ)/σ

Thus;

z = (42 - 50)/7

z = -1.14

Since we are looking for P (X > 42), then let's look up this z-value from the z-distribution table attached.

We have;

P(X > 42) = 0.1271