Solution 11798: Using the Manual-Fit Function on the TI-84 Plus Family or TI-Nspire™ Handheld in TI-84 Plus Mode.
How can I use the Manual-Fit function on the TI-84 Plus family or TI-Nspire handheld in TI-84 Plus mode?
Follow to the steps below to use the Manual-Fit function:
1) Press [MODE] and make sure FUNC is selected.
2) Press [GRAPH].
3) Press [STAT], press the right arrow to display the CALC menu, and select D:Manual-Fit. (The graph displays according to the Mode, Format, and Window settings, including any active functions and active StatPlot(s). The free-floating cursor is at the center of the display)
4) Use the cursor navigation keys to move the cursor to a desired location and press [ENTER]. The location is marked with a box.
5) Navigate to another point and press [ENTER] to mark a second point. A line containing the two points marked will automatically be drawn and the calculator will display the equation of the Manual-Fit Line in the form Y=mX+b, where m and b are the current values of the slope and y intercept (respectively). The current value of the first parameter (m) in the symbolic expression is highlighted.
6) To modify either m or b parameter select it and press [ENTER] for this example m is 1 and b is 2. Once you have entered your values press [ENTER] again and the calculator will display the revised parameter value in the symbolic expression Y=mX+b, and refresh the graph with the updated Manual-Fit Line.
7) Press [2nd][QUIT] to return to the main screen.
Please see the TI-84 Plus family guidebook for additional information.
Please Note: TI-Nspire users may refer to the TI-84 Plus family guidebook.