LEXIBOOK SC460 Owner's Manual page 72

Power Regression:
We suspect that x and y are connected by an equation of the type y=A x
and we try to confirm this hypothesis as follows:
x 0,5
y 1,4
We switch to the two-variable statistics mode and Pwr regression:
[MODE] 3 [ ] 1
[SHIFT][CLR] 1 [=]
Beginning of data input:
[.] 5 [,] 1 [.] 4 [DT]
1 [,] 2 [DT] ... etc.
[SHIFT] [S-SUM] 3 [=] -> n
We obtain the following values for A, B and r:
[SHIFT] [S-VAR] [ ][ ] 1 [=]
[SHIFT] [S-VAR] [ ][ ] 2 [=]
[SHIFT] [S-VAR] [ ][ ] 3 [=]
The power regression is confirmed because r=0,998.
We can therefore estimate that y ≈ 2x
4 [SHIFT] [S-VAR] [ ][ ][ ] 2 [=] -> 4 | 4.073878837
6 [SHIFT] [S-VAR] [ ][ ][ ] 1 [=] -> 6 | 8.479112672
Quadratic Regression:
We suspect that x and y are connected by an equation of the type
y= A+Bx+Cx  and we try to confirm this hypothesis as follows:
x 29
y 1,6
We switch to the two-variable statistics mode and quadratic regression:
[MODE] 3 [ ] 3
[SHIFT] [CLR] 1 [=]
Beginning of data input :
29 [,] 1 [.] 6 [DT]
50 [,] 23[.]5 [DT] ... etc.
[SHIFT] [S-SUM] 3 [=]
We obtain the following values for A, B, and C:
[SHIFT] [S-VAR] [ ][ ] 1 [=] -> A |
[SHIFT] [S-VAR] [ ][ ] 2 [=] -> B |
[SHIFT] [S-VAR] [ ][ ] 3 [=] -> C |
For x= 16 we obtain only one estimated value for y:
16 [SHIFT] [S-VAR] [ ][ ][ ] 3 [=]
Yet for y=20 we obtain two possible values for x:
20 [SHIFT] [S-VAR] [ ][ ][ ] 1 [=]
20 [SHIFT] [S-VAR] [ ][ ][ ] 2 [=]
If the value of y put forward does not have a real x solution, for example
y=56, your calculator will display Math ERROR.
7
SC460IM0237.indb 72
1 1,5 2
2 2,4 2,9
-> Pwr is displayed
-> Clear
| 4.
-> A | 1.994142059
-> B | 0.515317442
-> r | 0.998473288
1/2 = 2√x.
y ^
x ^
50 74 103
23,5 38 46,4
-> Quad is displayed
-> clear
-> n | 5.
-35.59856934
1.495939413
-6.71629667-03
-> 16
->
->
118
48
y ^
| -13.38291067
y ^
20 | 47.14556728
1
x ^
20 | 175.5872105

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20/6/07 15:28:13