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## Statistical Analysis of Data Using Regressions

TI-83 Graphing Calculator

• Enter data into lists: STAT, EDIT, enter data into L1 and L2. Data may be cleared from a list by selecting ClrList from the EDIT menu, entering the name of the list you want to clear, and hitting ENTER.
• Check STAT PLOT to ensure that you agree with the conditions for display of your data and that only one STAT PLOT is on: STAT PLOT. ENTER, ensure that PLOT 1 is ON and that appropriate conditions are set (usually, disconnected dots, X list=L1, Y list=L2, square).
• View graph of data by pushing GRAPH. Hit ZOOM 9 to make graph exactly fit data.
• Regression analysis of data: STAT, CALC, select type of regression you will be using. The calculator screen will now show the type of regression you selected with a blinking cursor.
• You must now tell the calculator where to find the data and where to put the function that represents the statistical analysis of the data for graphing: You will now enter L1 (found above the number 1), Comma, L2 (found above the number 2), Comma, VARS, Y-VARS Function, ENTER, Y1 ENTER, ENTER
• The regression equation will now be displayed for you to record, substituting the numerical values for a and b.
• When you push GRAPH, both the data plot and the regression line will be displayed on the graph for printing.

TI-85 Graphing Calculator

• Enter data into lists: When you press STAT, five menu keys are shown.
• Select EDIT to enter or edit lists of data. Enter data into the xStat and into the yStat lists. After you have selected these names, they are displayed in the STAT editor. If you want to clear all data in both lists, hit CLRxy from the STAT editor menu.
• Statistical analysis of data: Select CALC from the editor. The menu keys are labeled with the first five items of the statistical calculation menu. For example, LNR is for a linear regression. When you select the type of regression you want to use, it is calculated and the results are stored in the statistical result variables. These variables are recalled using the STAT VARS menu, selecting RegEq.
• Graphical analysis of data: To plot a graph of the data and its statistical analysis, select DRAW from the STAT menu. CLDRW will clear any existing drawings. DRREG draws the determined regression equation on the current graph of data.
• To display regression as “y” use Streg, type y1, ENTER.

TI-86 Graphing Calculator

• Enter data into lists: When you press STAT, the menu keys for the statistical menu are shown.
• Select EDIT to enter or edit lists of data. Enter data into the xStat and into the yStat lists. If you want to clear all data in a list, toggle up to either xStat or yStat and hit clear. The default value for the fStat column is one.
• Setting up a StatPlot: The StatPlot menu is found by using these keystrokes: 2nd, STAT, F3. You can turn your StatPlot off or on and decide upon the type of scatter plot to use(SCAT or xyline).
• Statistical analysis of data: Regression equations can be calculated from the STAT, Calc menu. LinR is for a linear regression. When you select your equation type and hit enter, the solution is displayed on the screen.
• Graphical analysis of data: To plot a graph of the data, select DRAW from the statistical menu. Your StatPlot is shown. You can also display the regression equation by selecting DRREG from this menu. To better display your data, select ZOOm, ZDATA from the GRAPH menu.

TI-82 Graphing Calculator

• Entering data into lists: STAT, EDIT, enter data into L1 and into L2. Data may be cleared from a list by selecting 1:Edit from the STAT EDIT menu, arrowing the cursor to the L1, etc. heading, CLEAR, ENTER.
• Check STAT PLOT to ensure that your STAT PLOT 1 is on and that you agree with all the settings. The typical settings are listed under the instructions for using the TI-83 calculator.
• Press GRAPH. Press ZOOM, then select 9:ZoomStat to display your graph of data.
• Statistical analysis of data: STAT, CALC, select regression. For example. 5: LinReg performs a linear regression. After hitting enter on your regression type you must identify the lists where the data is found. Press L1 (above the number 1), Comma, L2 (above the number 2), ENTER. This displays the regression equation. To graph the regression equation, you must now store it into y=. Select "y1=" , Comma, VARS, select 5:Statistics. Toggle over to EQ, select 7:RegEQ, Graph.
• Record the regression equation, substituting numerical values for a and b.

PRINTING USING TI GRAPH LINK

• Select appropriate graph link (TI-82 and TI-83 both can use TI-82 Graph Link). Select LINK. Follow on-screen instructions. If you are using a TI-83 graph link, the TI-83 must be on the home screen.