An Elementary School Teacher Has Three Classes

Multiple Choice

An elementary school teacher has three classes.She finds the following mean and standard deviations for student IQ scores.
She knows she is most effective when the students all have similar IQ levels.Which class is she likely to be most effective with?

A) Class #1
B) Class #2
C) Class #3
D) Classes #1 and #2 equally
E) Classes #1 and #3 equally