Linear Regression. Calculate r (the correlation coefficient), m, b, and as follows:
1.
Clear the statistical registers by pressing
2. Enter the first x-value and press
3. Enter the corresponding y-value and press
of pairs of items accumulated.
4. Continue entering x,y pairs. The n-value is increased with each entry.
5. To display r, the correlation coefficient, press
6. To display m, the slope, press
7.
To display b (the y-intercept), press
Linear Estimation. The straight line calculated by linear regression can be used to estimate a
y-value for a given x-value, or vice versa:
1.
Enter the x,y data.
2. Enter the known x-value or y-value.
•
To estimate x for the given y, enter the y-value, then press
•
To estimate y for the given x, enter the x-value, then press
Example: 4
Ali's Azaleas advertises on a local radio station. For the past six weeks, the manager has kept
records of the number of minutes of advertising that were purchased, and the sales for that
week.
Table 12-9 Recording the number of minutes of the advertisements and sales
Week
What is the y-intercept, the slope, and the correlation coefficient?
122
Statistical Calculations
Æ
\W\«
Minutes of Advertising
1
2
3
4
5
6
\t
.
. The x-value is displayed.
¡
. The HP 10bII+ displays n, the number
\Z\«
.
\T\«
\Z
\W
(x-values)
2
1
3
5
5
4
.
.
.
.
Sales
(y-values)
1,400
920
1,100
2,265
2,890
2,200