Table :

A-4b

Calculating the Sum of the Cross-Products

Person

Hours Studied (X)

GPA (Y)

zx

zy

zx zy

Candace

8

3.8

   0.75

 1.07

0.80

Denise

2

2   

−1.15

−1.13

1.30

Joaquin

2

2.3

−1.15

−0.76

0.88

Jon

7

3.4

   0.44

 0.58

0.25

Milford

5

2.4

−0.20

−0.64

0.13

Rachel

5

2.5

−0.20

−0.52

0.10

Shawna

1

1.7

−1.46

−1.50

2.19

Leroi

9

3.7

   1.07

 0.95

1.01

Jeanine

6

3.2

   0.12

 0.34

0.04

Marisol

10  

4   

   1.38

 1.31

1.82

Lee

2

1.5

−1.15

−1.74

2.00

Rashid

9

3.9

   1.07

 1.19

1.27

Sunny

3

2.6

−0.83

−0.40

0.33

Flora

6

3   

   0.12

 0.09

0.01

Kris

4

2.9

−0.51

−0.03

0.02

Denis

11  

3.9

   1.70

 1.19

2.02

Σ zxzy = 14.16