In a test of the hypothesis that females smile at others more than males do, females and

Question:

In a test of the hypothesis that females smile at others more than males do, females and males were videotaped while interacting and the number of smiles emitted by each sex was noted. Using the following number of smiles in the 5-minute interaction, test the null hypothesis that there are no sex differences in the number of smiles.
Males Females
8…………………. 15
11…………………. 19
13…………………. 13
4…………………. 11
2…………………. 18