In a statisticsclass, the standard deviation of the heights of all students was 3.9 inches. The standard deviation of the heights of males was 3.3 inches and the standard deviation of females was 3.1inches. Why is the standard deviation of the entire class more than the standard deviation of the males and females consideredseparately?

A.

The standard deviation of the entire class is more than the standard deviation of the males and females considered separately because the smaller thesample, the smaller the sample standard deviation.

B.

The standard deviation of the entire class is more than the standard deviation of the males and females considered separately because the male and female sample sizes are smaller than the sample of the entire class.

C.

The standard deviation of the entire class is more than the standard deviation of the males and females considered separately because the distribution of the entire class has more dispersion.

D.

The standard deviation of the entire class is more than the standard deviation of the males and females considered separately because there is more dispersion in the male and female samples than the entire class.