HP -22S Owner's Manual page 66

Linear Estimation. To do linear estimation calculations:
1. Enter the x,y-data using the instructions on page 61.
2. If you want to see the slope, y-intercept, and/or correlation coef-
ficient for· the linear regression fit, you can do so by pressing
! STAT I
{L.R.}
{m},! STAT I
{L.R.}
{b}, and ! STAT I
{L.R. }
{r} .
3. Key in the known x-value or y-value.
4. Press! STAT I
{L.R.}.
Then:
• To estimate
x
for the given
y,
press
{i} .
• To estimate
y
for the given x, press
{y}.
See chapter 8 for an alternative way of doing linear estimation using
!EVALI.
Example: Linear Regression and Estimation.
Part 1.
After re-
ceiving C grades in their first statistics exam, four students sought
help from Paul
J.
McTutor. Because Paul loves numbers, he recorded
the following data based on the results of their second exam:
X Hours of tutoring
1 3 4 6
Y Grade
64 88 76 98
Calculate the correlation coefficient and y-intercept for the data.
Keys: Display: Description:
. !
CLEAR I
{I}
Clears the statistical
registers.
1 !INPUT I 64 !
~+
I
Enters the x,y-data.
3 !INPUT I 88 !
~+
I
4 I INPUT I 76 !
~+
I
6 II NPUT
I
98 I
~+
I
n=4.13131313
I STAT I {L.R. }
{r}
r =13.8587
Calculates the correla-
tion coefficient.
I STAT I {L.R.}
{b} b=613.23138
Calculates the y-
intercept.
66 5: Statistical Calculations