Casio fx-5800P User Manual page 86

Example 2: The nearby data shows how the weight of a
newborn at various numbers of days after birth.
Obtain the regression formula and correlation coeffi cient
produced by linear regression of the data.
Obtain the regression formula and correlation coeffi cient
produced by logarithmic regression of the data.
Predict the weight 350 days after birth based on the
regression formula that best fi ts the trend of the data in
accordance with the regression results.
Operation Procedure
Select the REG Mode:
Select FreqOff for the statistical frequency setting:
Input the number of day data into the X-column:
20
200
Input the weight data into the Y-column:
7940
9270
(1) Linear Regression
Display the linear regression calculation result screen:
(2) Distribution Logarithmic Regression
Display the logarithmic regression calculation result screen:
(3) Weight Prediction
The absolute value of correlation coeffi cient r is close to 1, so logarithmic regression is used
for its calculation.
x
Obtain when = 350:
J
4 (REG)
5 (STAT) 2 (FreqOff)
(SETUP)
50 80
230
3150 4800
8690
9310
6 (RESULT) 2 (Reg) 1 (Line)
J 6 (RESULT) 2 (Reg) 3 (Log)
1 ( / COMP) 350
2 (VAR)
110 140
260 290
6420
8800
9390
7 (STAT)
7 ( )
E-85
Number Weight
of Days
20
50
80
110
140
170
200
230
260
290
320
170
320
7310
9130
(g)
3150
4800
6420
7310
7940
8690
8800
9130
9270
9310
9390