Arden and Plomin (2006) published a study reporting that IQ scores for boys are more variable than IQ scores for girls. A researcher would like to know if this same phenomenon applies to other measures of cognitive ability. A standard cognitive skills test is given to a sample of n 5 15 adolescent boys and a sample of n 5 15 adolescent girls, and resulted in the following scores.

a. Compute the mean, the variance, and the standard deviation for each group.

b. Is one group of scores noticeably more variable than the other?