Key

Meaning (Continued)

 

 

 

Displays ZOOM menu.

 

Turns trace mode on/off. The white

 

box appears next to the option when

 

Trace mode is active.

 

Turns fit mode on or off. Turning

 

on draws a curve to fit the data points

 

according to the current regression

 

model.

(2var

Enables you to specify a value on the

statistics only)

line of best fit to jump to or a data

 

point number to jump to.

 

Displays the equation of the

 

regression curve.

 

Hides and displays the menu key

 

labels. When the labels are hidden,

 

any menu key displays the (x,y)

 

coordinates. Pressing

 

redisplays the menu labels.

 

 

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 to move to the regression curve.

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

In HOME:

Enter PREDX(y-value) to find the predicted value for the independent variable given a hypothetical dependent value.

10-20

Statistics aplet

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Image 122
HP 39gs Graphing Calculating predicted values, Find predicted values, According to the current regression, Model, 2var