Asample with which of these variances has a standard deviation that is greater than the variance?
a. 0.25
b. 1.75
c. 2.5
d. 1.5

Standard deviation is simply the square root of the variance. 

We need to get the square root of each variance to see whether its standard deviation is greater than its variance.

A. 0.25 ⇒ √0.25 = 0.50
B. 1.75 ⇒ √1.75 = 1.32
C. 2.5 ⇒ √2.5 = 1.58
D. 1.5 ⇒ √1.5 = 1.22

Among the choices, only A. 0.25 has a standard deviation that is greater than the variance. The standard deviation is 0.50