A researcher wants to investigate whether the first year male and female students at a university differ in their memory abilities. Ten students of each group were randomly selected from the first year enrollment roll to serve as subjects. All 20 subjects were read 30 unrelated words and then asked to recall as many of the words as possible. The number of words correctly recalled by each subject were recorded as follows.

Males: 16 14 18 25 17 14 19 21 16 17

Females: 24 23 26 17 18 20 23 26 24 20