0.7 Notes for the ti-83, 83+, 84, 84+ calculators  (Page 2/3)

To deselect equations:

1. Access the list of equations.
   

2. Select each equal sign (=).
   

3. Continue, until all equations are deselected.

To clear equations:

1. Access the list of equations.
   

2. Use the arrow keys to navigate to the right of each equal sign (=) and clear them.
   

3. Repeat until all equations are deleted.

To draw default histogram:

1. Access the ZOOM menu.
   

2. Select <9:ZoomStat> .
   

3. The histogram will show with a window automatically set.

To draw custom histogram:

1. Access window mode to set the graph parameters.
   
2. • $X_{\min }=\mathrm{–2.5}$
   • $X_{\max }=3.5$
   • $X_{scl}=1$ (width of bars)
   • $Y_{\min }=0$
   • $Y_{\max }=10$
   • $Y_{scl}=1$ (spacing of tick marks on y -axis)
   • $X_{res}=1$
3. Access graphing mode to see the histogram.
   

To draw box plots:

1. Access graphing mode.
   , [STAT PLOT]

2. Select <1:Plot 1> to access the first graph.
   

3. Use the arrows to select <ON> and turn on Plot 1.
   

4. Use the arrows to select the box plot picture and enable it.
   

5. Use the arrows to navigate to <Xlist> .

6. If "L1" is not selected, select it.
   , [L1] ,

7. Use the arrows to navigate to <Freq> .

8. Indicate that the frequencies are in [L2] .
   , [L2] ,

9. Go back to access other graphs.
   , [STAT PLOT]

10. Be sure to deselect or clear all equations before graphing using the method mentioned above.

11. View the box plot.
    , [STAT PLOT]

Linear regression

Sample data

The following data is real. The percent of declared ethnic minority students at De Anza College for selected years from 1970–1995 was:

Student ethnic minority percentage

To enter data and do linear regression:

1. ON Turns calculator on.
   

2. Before accessing this program, be sure to turn off all plots.

   • Access graphing mode.
     , [STAT PLOT]

   • Turn off all plots.
     ,

3. Round to three decimal places. To do so:

   • Access the mode menu.
     , [STAT PLOT]

   • Navigate to <Float> and then to the right to <3> .
     

   • All numbers will be rounded to three decimal places until changed.
     

4. Enter statistics mode and clear lists [L1] and [L2] , as describe previously.
   ,

5. Enter editing mode to insert values for x and y .
   ,

6. Enter each value. Press to continue.

To display the correlation coefficient:

1. Access the catalog.
   , [CATALOG]

2. Arrow down and select <DiagnosticOn>
   ... , ,

3. $r$ and $r^2$ will be displayed during regression calculations.

4. Access linear regression.
   

5. Select the form of y = a + bx .
   ,

The display will show:

Linreg

• y = a + bx
• a = –3176.909
• b = 1.617
• r = 2 0.924
• r = 0.961

This means the Line of Best Fit (Least Squares Line) is:

• y = –3176.909 + 1.617 x
• Percent = –3176.909 + 1.617 (year #)

To see the scatter plot:

1. Access graphing mode.
   , [STAT PLOT]

2. Select <1:plot 1> To access plotting - first graph.
   

3. Navigate and select <ON> to turn on Plot 1.
   <ON>

4. Navigate to the first picture.

5. Select the scatter plot.
   

6. Navigate to <Xlist> .
7. If [L1] is not selected, press , [L1] to select it.

8. Confirm that the data values are in [L1] .
   <ON>

9. Navigate to <Ylist> .

10. Select that the frequencies are in [L2] .
    , [L2] ,

11. Go back to access other graphs.
    , [STAT PLOT]

12. Use the arrows to turn off the remaining plots.
13. Access window mode to set the graph parameters.
    
    • $X_{\min }=1970$
    • $X_{\max }=2000$
    • $X_{scl}=10$ (spacing of tick marks on x -axis)
    • $Y_{\min }=-0.05$
    • $Y_{\max }=60$
    • $Y_{scl}=10$ (spacing of tick marks on y -axis)
    • $X_{res}=1$
14. Be sure to deselect or clear all equations before graphing, using the instructions above.
15. Press the graph button to see the scatter plot.