Question

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

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

Answer 1

Answer:The mean score on a physics test was 75 points. Amy’s score was 67 points, which was 2 standard deviations below the mean.

What is the variance of the data set?

2

4

8

16 <<<<<<<CORRECT

Explanation:

EDGE 2021

Answer 2

D.16

Explanation:

We know that the standard deviation is the square-root of variance. (+ve sqrt)

Therefore, the variance = (S.D)^2 = 16

And now..we go for the second question.............

The z score for a person with marks x is given by (x-mean)/(SD)

Putting in the known values,

Required z-score = (7-13)/4 = -6/4 = -1.5