Quadratic regression
The regression equation for quadratic regression is:
D
y = A+Bx+Cx
Example 1:
xi
29
50
74
103
118
In REG mode:
(Quad)
(Scl)
(Regression coefficient A)
(Regression coefficient B)
(Regression coefficient C)
(
when xi = 16)
(
when yi = 20)
1
(
when yi = 20)
2
Precautionary measures when entering data
Pressing
D
The same data value can be entered repeatedly by using the key
D
sequence
and 30" five times, use the key sequence 20
You can enter the above results in any sequence, i.e. not necessarily
D
in the order described.
The precautionary measures applicable for editing for standard
D
deviation also apply for regression calculations.
Do not use variables A to F, X or Y for saving data when you are
D
performing statistical calculations. These variables are used as
temporary memory areas for statistical calculations so that data
assigned to these variables can be replaced by other data during
statistical calculations.
By activating REG mode and selecting a regression type (Lin, Log,
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Exp, Pwr, Inv, Quad), the variables A to F, X and Y are cleared.
These variables are also cleared when you switch from one
regression type to another when REG is active.
2
yi
1.6
23.5
38.0
46.4
48.0
(Stat clear)
29
1.6
74
38.0
16
20
20
enters the same data twice.
. In order, for example, to enter data values "20
Execute quadratic regression in order to determine
the terms of the regression equation for the adjacent
data. Then use the regression equation to estimate
y
the values of
(estimated value of y) for xi = 16 and
ƒ
(estimated value of x) for yi = 20.
50
23.5
103
46.4
118
48.0
61
-35.59856934
1.495939414
-6.71629667
-13.38291067
47.14556728
175.5872105
30
5
-03
.