Question

If the mean of a data set is 100 and almost all the data is from 40 to 160, what is a good approximation of the variance?

A) 120
B) 20
C) 900
D) 400
E) none of the above

Answer 1

A.) 120

The variance is the range of a data set, which shows how spread out numbers are. To get the variance, we take the last number and subtract it from the first number. 160-40=120. Therefore, there is 120 numbers between 40 to 160.