If the mean weight of all students in a class is 165 pounds with a variance of 234.09 square pounds, what is the z-value associated with a student whose weight is 140 pounds?

Step-by-step explanation:

The z-score measures how many standard deviation a score X is above or below the mean.

it is given by the following formula:

In which

is the mean, is the standard deviation

In this problem, we have that:

Mean weight of all students in a class is 165 pounds, so

Variance of 234.09 square pounds. The standard deviation is the square root of the variance. So

What is the z-value associated with a student whose weight is 140 pounds?

Z when X = 140. So