A social psychologist is interested in knowing whether the experience of attending preschool is related to subsequent sociability. She identifies two groups of first graders, those who attended preschool and those who had not. Based on observations in the classroom and playground each student is assigned a sociability score. The following sociability results were obtained: Attended preschool: n1 = 16, Sum of X1 = 204, Sum of X1 2 = 3660 Did not attend preschool: n2 = 16, Sum of X2 = 248, Sum of X2 2 = 3998

a) State the null and alternative hypotheses in symbolic and text forms.

b) Calculate the test statistic.

c) Determine the critical value (t.05).

d) Make decision on the null hypothesis and draw conclusions.