Casio CLASSPAD 330 3.04 - Page 407

20060301
Cubic Regression
Model Formula:
y
=
a
·
x
3
+
b
·
x
2
+
c
·
x
+
d
a
: cubic regression coefficient
b
: quadratic regression coefficient
c
: linear regression coefficient
d
: regression constant term (
y
-intercept)
r
2
: coefficient of determination
MSe
: mean square error
Quartic Regression
Model Formula:
y
=
a
·
x
4
+
b
·
x
3
+
c
·
x
2
+
d
·
x
+
e
a
: quartic regression coefficient
b
: cubic regression coefficient
c
: quadratic regression coefficient
d
: linear regression coefficient
e
: regression constant term (
y
-intercept)
r
2
: coefficient of determination
MSe
: mean square error
• MSe =

1
n – 4
i=1
n
(yi – (a·xi
3
+ b·xi
2
+ c·xi +d ))
2
• MSe =

1
n – 5
i=1
n
(y i – (a·x i
4
+ b·x i
3
+ c·x i
2
+ d·x i + e))
2
7-5-8
Graphing Paired-Variable Statistical Data