or
or
∑
∑
∑
∑
∑
xi yi
= 44328.69
xi −HSA
= 44328.69
x i2−HSA yi −GPA
= 1135204
= 591.01
yi2 −GPA
= 1799.43
n = 200 r= r=
∑
xi yi
−(∑ x )(∑ y ) / n i i
2
"
∑ xi 2 −(∑ xi ) / n%"∑ yi 2 −(∑ yi ) / n%
$
'$
'
#
&
2
44328.69 − (14734)(591) / 200
"1135204 − (44328.69) 2 / 200$"1799.43− (591) 2 / 200$
#
%#
%
= 0.48437
b. Correlation between English ACT scores and GPA (15 points) • Use can use the excel function CORREL (data colum1, data column2) or minitab
∑
∑
∑
∑
∑
xi yi
= 13849.35
= 4634
xi −ENG x i2−ENG yi −GPA y i2−GPA
n = 200
= 110612
= 591.01
= 1799.43
∑
r=
xi yi
−(∑ x )(∑ y ) / n i i
2
2
"
%"
%
2
2
$∑ xi −(∑ xi ) / n'$∑ yi −(∑ yi ) / n'
#
&
13849.35− (4634)(591) / 200
"110612 − (4634) 2 / 200$""1799.43− (591) 2 / 200$$
#
%##
%%
r=
= 0.37594181
Correlation between Math ACT scores and GPA Use can use the excel function CORREL (data colum1, data column2) or minitab
∑
∑
∑
∑
∑
xi yi
= 14051.28
xi −MATH x i2−MATH yi −GPA
= 4713
= 114095
= 591.01
yi2 −GPA
= 1799.43
n = 200
∑
r=
xi yi
−(∑ x )(∑ y ) / n i i
2
"
∑ xi 2 −(∑ xi ) / n%"∑ yi 2 −(∑ yi ) / n%
$
'$
'
#
&
2
14051.28 − (4713)(591) / 200
"114095− (4713) 2 / 200$"1799.43− (591) 2 / 200$
#
%#
%
r=
= 0.310100412
Correlation between Comp ACT scores and GPA Use can use the excel function CORREL (data colum1, data column2) or minitab
∑
∑
∑
∑
∑
xi yi
= 14173.71
xi −COMP x i2−COMP
= 114676
= 591.01 y −GPA i y i2−GPA
n = 200
= 4748
= 1799.43
r=
r=
∑
xi yi
−(∑ x )(∑ y ) / n i i
2
2
"
%"
%
2
2
$∑ xi −(∑ xi ) / n'$∑ yi −(∑ yi ) / n'
#
&
14173.71− (4748)(591)