In a test of hypothesis that females smile more than males do, females and males were videotaped while interacting and the number of smiles emitted by each sex was noted. Using the data in the table 1 for the number of smile in the 5minuite interaction, and the steps in hypothesis testing; test the null hypothesis that there are no sex differences in the number of smiles.

Table 1
Males Females
8 15
11 19
13 13
4 11
2 18