Calculating Estimated Values - Casio fx-82AU PLUS II User Manual

Results: Mean: 3, Population Standard Deviation: 1.154700538
Example 3: To calculate the linear regression and logarithmic regression
correlation coefficients for the following paired-variable data and determine
the regression formula for the strongest correlation: (x, y) = (20, 3150),
(110, 7310), (200, 8800), (290, 9310). Specify Fix 3 (three decimal places)
for results.
(SETUP)
20
3150
Results: Linear Regression Correlation Coefficient: 0.923
Logarithmic Regression Correlation Coefficient: 0.998
Logarithmic Regression Formula: y = -3857.984 + 2357.532lnx

Calculating Estimated Values

Based on the regression formula obtained by paired-variable statistical
calculation, the estimated value of y can be calculated for a given x-value.
The corresponding x-value (two values, x
regression) also can be calculated for a value of y in the regression
formula.
Example 4: To determine the estimate value for x when y = -130 in the
regression formula produced by logarithmic regression of the data in
Example 3. Specify Fix 3 for the result. (Perform the following operation
after completing the operations in Example 3.)
130
Important!
• Regression coefficient, correlation coefficient, and estimated value calculations can
take considerable time when there are a large number of data items.
(STAT) (Var)
(STAT)
(SETUP)
(STAT)
110 200 290
7310 8800
(STAT) (Reg)
(STAT) (Type)
(STAT) (Reg)
(STAT) (Reg)
(STAT) (Reg)
(STAT) (Reg)
41
(σ )
x
(OFF)
(Fix)
(A+BX)
9310
(r)
(ln X)
(r)
(A)
(B)
and x , in the case of quadratic
1 2
(x ˆ )
1.154700538
0.923
0.998
-3857.984
2357.532
4.861