An instructor has a class of 23 students. At the beginning of the semester, each student is randomly assigned to one of four teaching assistants—Smiley, Haydon, Alleline, or Bland. The students are...

An instructor has a class of 23 students. At the beginning of the semester, each student is randomly assigned to one of four teaching assistants—Smiley, Haydon, Alleline, or Bland. The students are encouraged to meet with their assigned teaching assistant to discuss difficult course material. At the end of the semester, a common examination is administered. The scores obtained by students working with these teach- ing assistants are shown in the accompanying table.



Smiley   Haydon    Alleline    Bland

72            78             80           79
69             93            68           70
84            79             59           61
76            97             75           74
64            88             82           85
                81             68           63


a. Calculate the within-groups, between-groups, and total sum of squares.
b. Complete the analysis of variance table and test the null hypothesis of equality of population mean scores for the teaching assistants.