HP 12C Platinum User Manual page 98

98 Section 6: Statistics Functions
Example: Check the reliability of the linear estimate in the preceding example by
displaying the correlation coefficient.
Keystrokes
~
To graph the regression line, calculate the coefficients of the linear equation
y = A + Bx.
1. Press 0gR to compute the y-intercept (A).
2. To compute the slope of the line (B) in RPN mode, press
1gR~d~-. To compute the slope of the line (B) in ALG mode,
press these keys: 1gR~d-~}.
Example: Compute the slope and intercept of the regression line in the preceding
example.
Keystrokes
(RPN mode)
0gR
1 gR~d~-
Keystrokes
(ALG mode)
0gR
1gR~d-~}
The equation that describes the regression line is:
Display
The correlation coefficient is close
0.90
to 1, so the sales calculated in the
preceding example is a good
estimate.
Display
y-intercept (A); projected value for x
15.55
= 0.
Slope of the line (B); indicates the
0.001
change in the projected values
caused by an incremental change
in the x value.
Display
y-intercept (A); projected value for x
15.55
= 0.
Slope of the line (B); indicates the
0.001
change in the projected values
caused by an incremental change
in the x value.
y = 15.55 + 0.001x