Data and the TI-‐NspireTM CX Entering Data and Determining Trend Lines and Regressions 1. Open a new TI-‐Nspire CX document and choose “Lists and Spreadsheets”. 2. Enter an appropriate title for the independent and dependent values in the top row of the page, next to the “A” and “B” column headings. 3. Enter the data in these columns, making sure that there is the same number of data values in each column.
Figure 1
4. When you finish typing all data values, make sure that the cursor is blue and in one of the columns containing data. (See Figure 1)
Figure 2
5. Press “Menu” “Data” “Quick Graph.” (See Figure 2) 6. Determine the appropriate independent and dependent values. Move the cursor just below the x axis and press “Click” to select the independent term, and move to just to the left of the y-‐axis, then press “Click” to select the dependent term. (See Figure 3) 7. Next, press “Menu” “Analyze” “Add Moveable Figure 3 Line” (See Figure 4)
Figure 4
8. A random line will be placed on the graphed data. 9. When the cursor is moved to the center of this line, the cursor takes the form of a cross. When you press and hold “Click” to grab the line and then slide your finger around the touchpad, the line will be translated. Press “Click” again to release the grab feature. 10. When the cursor is moved to an end of the line, Figure 5 the cursor becomes a broken circle. When you press and hold “Click” to grab the line and then slide your finger around the touchpad, the line will be rotated. (See Figure 5). Press “Click” again to release the grab feature. 11. Adjust the moveable line as appropriate to create a trend line so that you can make predictions based on your data. 12. If you cannot see the entire equation, hover over the line and press and hold “Click” to grab the equation and move it to a convenient location or press “Doc” “Page Layout” “Ungroup” to change Figure 7 the split screen to two separate pages. 13. Press “Menu” “Analyze” “Show Regression” (See Figure 6) and choose the appropriate regression equation (See Figure 7)
Figure 6
Determining a Regression Equation with the Correlation Coefficient 1. Open a new TI-‐Nspire CX document and choose “Lists and Spreadsheets”. 2. Enter an appropriate title for the independent and dependent values in the top row of the page, next to the “A” and “B” column headings.
3. Enter the data in these columns, making sure that there is the same number of data values in each column.
Figure 1
4. When you finish typing all data values, make sure that the cursor is blue and NOT in one of the columns containing data. (See Figure 1) 5. Press “Menu” “Statistics” “Stat Calculations,” select the appropriate regression, and press the arrows at the end of the “X List” and “Y List” fields in order to select the appropriate independent and dependent titles. (See Figure 2) st 6. Make sure that the “1 Result Column” selected does not contain a column name where your data is located.
Figure 2
7. The regression equation will be displayed. Notice the location of the correlation coefficient “r”. (See Figure 3)
Figure 3
Do you want to adjust a point on the graph and/or List? On the graph, move your cursor and hover the point in question. Then press and hold “Click” and slide your finger across the TouchPad to adjust the location of the point. OR, on the List and Spreadsheet, double click on the incorrect coordinate in the List and retype with the value that you want. With either method, when you make a change, the corresponding regression equation will change as well.
CAMT 2017 Session 2171 The TI-‐NspireTM CX Technology—Activities for Beginners Valerie Hudson Texas Instruments Instructor
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