HP 49g Graphing Calculator - Manual (Page 174)

Predicting a value based on the regression
Once you have perfomied a regression, you can use it to predict y values.
1. Follow steps 1 to 5 in the previous section to apply a regression to your
data.
2. Press
PRBD.
The Predict Values input form is displayed.
3. In tire X field, enter the value for which you want to find the
corresponding y value.
4. Move the cursor to the Y field and press
PRED.
The computed value,
based on the regression, appears.
Although you can use this method to predict a value for .x that
corresponds to a Imown у value, the solution may not be
mathematically correct.
Calculating summary statistics
: You can use the summary statistics application to calculate up to six
summary statistics on bivariate data.
To calculate summaiy statistics:
1. Use the method described in “Starting an application and specifying
the data” on page 9-2 to open the Summary Statistics input form and to
load the data to analyze.
2. In the X-Col and Y-Col fields, specify the cohmms that hold the data to
analyze.
3. Use the arrow keys to navigate aroimd the Calculate fields. Press
chk
to choose the values that you want to calculate. A check mark appears
against the ones you choose. The summary statistics that can be
calculated are as follows:
2X The sum of the values in the X-Col of ZD AT.
ZY The siun of the values in the Y-Col of ZD AT.
ZX2 The sum of the squares of the values iir the X-Col of ZD AT.
ZY2 The sum of the squares of the values in the Y-Col of ZD AT.
ZXY The sum of the products of the X-Col and Y-Col pairs of ZD AT
NZ The nmnber of rows in ZD AT.
4. Press
OK
to calculate the statistics. The statistics appear in history.
Page 9-6 Using statistics