ASSIGNMENT 13
SIMPLE REGRESSION
PROBLEM: The following is a table employment test score (X) and job performance (Y) of a sample of
employees in a certain company.
Required : Derive a simple regression equation for predicting job performance from employment test
score. Predict performance rating if employment test score= 87.
1. Mean
a.
X=ΣX
n
=
824
15
= 54.93
b.
Y=ΣY
n
=
1173
15
= 78.20
2. Slope
b =
n Σ XY −Σ X Σ Y
n Σ X 2−¿¿
¿15
(
66090
)
−(824 )(1173 )
15
(
53970
)
−¿¿
=
991350−966552
809550−678976
= 0.1899
X Y XY X2
78 82 6396 6084
42 77 3234 1764
89 85 7565 7921
50 75 3750 2500
30 75 2250 900
25 72 1800 625
78 80 6240 6084
90 90 8100 8100
47 76 3572 2209
35 73 2555 1225
28 70 1960 784
18 75 1350 324
80 77 6160 6400
73 86 6278 5329
61 80 4880 3721
Σ X=¿
824
Σ Y =¿
1173
Σ XY =¿
66090
Σ X2=¿
53970
