20060301
Drawing an Exponential Regre
ss
ion Graph (
y
=
a
·
e
b
·
x
)
Exponential regression can be used when
y
is proportional to the exponential function of
x
. The normal exponential regression formula is
y
=
a
·
e
b
·
x
. If we obtain the logarithms of
both sides, we get ln(
y
) = ln(
a
) +
b
·
x
. Next, if we say that Y = ln(
y
) and A = In(
a
), the formula
corresponds to the linear regression formula Y = A +
b
·
x
.
S
Cla
ss
Pad Operation
Start the graphing operation from the Statistics application’s Graph window or List window.
From the Graph window
Tap [Calc] [Exponential Reg] [OK] [OK]
.
From the Li
s
t window
Tap [SetGraph][Setting...], or
'
.
On the Set StatGraphs dialog box that appears, configure a StatGraph setup with the
setting shown below, and then tap [Set].
Type:
ExpR
Tap
x
to draw the graph.
7-5-10
Graphing Paired-Variable Statistical Data
The following is the exponential regression model formula in this case.
y
=
a
·
e
b
·
x
a
: regression
coefficient
b
:
regression constant term
r
: correlation
coefficient
r
2
:
coefficient of determination
MSe
: mean square error
• MSe
=
1
n
–
2
i
=1
n
(
ln
(
y
i
)
– (
ln
(
a
)
+
b·x
i
))
2
··
Summary of Contents for ClassPad 330
Page 11: ...20060301 20090601 ClassPad 330 ClassPad OS Version 3 04 ...
Page 277: ...20060301 3 3 10 Storing Functions 3 Tap AND Plot OR Plot ...
Page 779: ...20090601 S Graph Line Clustered C S Graph Line Stacked E 13 9 2 Graphing ...
Page 780: ...20090601 S Graph Line 100 Stacked F S Graph Column Clustered G 13 9 3 Graphing ...
Page 781: ...20090601 S Graph Column Stacked I S Graph Column 100 Stacked J 13 9 4 Graphing ...
Page 782: ...20090601 S Graph Bar Clustered K S Graph Bar Stacked 9 13 9 5 Graphing ...
