Scatter Plots on the TI73

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Scatter Plots on the TI-73
This Power Point is to help guide someone through
the following

• Create a scatter plot using lists
• Find the equation for the line of best fit
• 3. Predict using the equation for the line of
  best fit

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Scatter Plots on the TI-73

• Putting Data in Lists
• Hit the LIST button
• Enter data under L1
• Type 1, 2, 3, 4, 5, 6
• Hit ENTER after entering the 6
• 4. Hit the right arrow

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Scatter Plots on the TI-73

• Now enter data under L2
• Type 15, 20, 28, 32, 35, 40
• Hit ENTER after entering the 40
• 7. Now we are ready to display our scatter plot!

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Scatter Plots on the TI-73

• Hit 2ND and Y
• Hit ENTER on the 1
• There is a cursor blinking on the On
• Hit ENTER on the ON this turns on Plot1
• Make sure that Xlist has L1 and Ylist has L2

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Scatter Plots on the TI-73

• Hit ENTER on the first option after Type
• Hit the WINDOW button
• 15. Set a range for x and y that fits your data

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Scatter Plots on the TI-73

• Use the following for the example data
• Xmin 0
• Xmax 10
• Xscl 1
• Ymin 0
• Ymax 50
• Yscl 5

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Scatter Plots on the TI-73

• Now hit GRAPH a scatter plot should appear
• Now we can find the line of best fit for the
  scatter plot
• Hit 2ND and LIST
• 20. Arrow over to CALC

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Scatter Plots on the TI-73

• Arrow down to
• 5 LinReg(axb)
• Hit ENTER and you should see LinReg(axb)
• Hit ENTER again and you should see the
  information that gives you the equation for the
  line of best fit

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Scatter Plots on the TI-73

• You should see
• yaxb
• a4.971428571
• b10.93333333
• Now we need to get the
• equation into Y so that
• it will be graphed

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Scatter Plots on the TI-73

• Hit 2ND Y
• You should now see a
• Cursor blinking beside
• Y1
• Hit 2ND APPS
• Arrow DOWN and hit ENTER on 3Statistics...

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Scatter Plots on the TI-73

• Now Arrow RIGHT to EQ and hit ENTER on 1RegEQ
• The equation for the line of best fit should be
  in the Y1
• Y14.9714285714287X
• 10.933333333333

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Scatter Plots on the TI-73

• 30. Now hit GRAPH and the graph of the
  regression line should appear!

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Using the Line of Best Fit to Predict

• Hit 2ND WINDOW and you now have options for your
  TABLE SETUP
• Hit ENTER on Ask over from Indpnt
• 3. Hit ENTER on Auto over from Depend

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Using the Line of Best Fit to Predict

• Hit 2ND GRAPH
• Now type in a value for X under the X column
• For example Type in 20 and you should get 110.36