A random variable X is normally distributed with a mean of 150 and a variance of 36. Given that X = 120, then its corresponding z-score is 5.0.

Question

Quizplus · Accepted Answer

The formula for calculating the z-score is:

z = (X - mean) / standard deviation

The standard deviation is the square root of the variance, so in this case, the standard deviation = √36 = 6.

Using the formula, we get:

z = (120 - 150) / 6 = -5

Therefore, the corresponding z-score is -5, not 5.

The correct answer is B) False.

A Random Variable X Is Normally Distributed with a Mean