HP 40gs hp 40gs_user's guide_English_E_HDPMSG40E07A.pdf - Page 124

hp40g+.book Page 20 Friday, December 9, 2005 1:03 AM 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 statistics only) Enables you to specify a value on the 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 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. Find predicted values 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