HP 40G manual Calculating predicted values, Find predicted values

Calculating predicted values

Find predicted values

The functions PREDX and PREDY estimate (predict) values for X or Y given a hypothetical value for the other. The estimation is made based on the curve that has been calculated to fit the data according to the specified fit.

1.In Plot view, draw the regression curve for the data set.

2.Press e, to move to the regression curve.

3.Press *272_and enter the value of X. The cursor jumps to the desired point on curve and the coordinate display shows X and the predicted value of Y.

In HOME,

–Enter PREDX(y-value) >(17(5@

to find the predicted (estimated) value for the independent variable given a hypothetical dependent value.

–Enter PREDY(x-value) to find the predicted value of the dependent variable given a hypothetical independent variable.

You can type PREDX and PREDY into the edit line, or you can copy these function names from the MATH menu under the Stat-Two category.

H I N T In cases where more than one fit curve is displayed, the PREDY function uses the most recently calculated curve. In order to avoid errors with this function, uncheck all fits except the one that you want to work with, or use the Plot View method.

Statistics aplet 8-21