The standard deviation of a data set is 4. What is the variance?

a. 2
b. 4
C. 8
d. 16

The variance is the square of the standard deviation. Therefore, the variance of a data set with a standard deviation of 4 is 16.

Answer: d. 16

To find the variance, we need to square the standard deviation.

Given that the standard deviation is 4, we can find the variance by squaring 4.

Variance = (Standard Deviation)^2 = 4^2 = 16.

Therefore, the correct answer is d. 16.