NAME: BEST FIT LINES USING THE NSPIRE

Transcription

1 NAME: BEST FIT LINES USING THE NSPIRE For this portion of the activity, you will be using the same data sets you just completed where you visually estimated the line of best fit..) Load the data sets into the NSpire in the first and second column..) Set up a scatter plot. 3.) Find the Pearson r, a.k.a. correlation coefficient. 4.) Use the Linear Regression feature of the NSpire and compare it to the functions you wrote when you visually estimated the line of best fit. a.) Load this data into the NSpire. - Press Menu. - Select 3: Add Lists & Spreadsheets

2 - Use the up arrow on the Nav Pad and highlight the A portion (naming section) of the first column. - Label the first column x. - Use the right arrow and up arrow of the Nav Pad and highlight the B portion (naming section) of the second column. - Label the second column y. - Use the left arrow and down arrow of the Nav Pad and put the cursor beneath the first column in row. - Enter the x values into the first column. Press Enter after each data entry. - Use the right arrow and up arrow of the Nav Pad and put the cursor beneath the second column in row. - Enter the y values in the second column. Press Enter after each data entry. NOTE: You can not see all the data on the screen shot above.

3 Set up a scatter plot. - Press Ctrl I to insert a new page. - Select 5: Add Data & Statistics - Use the Nav Pad and follow the directions on the screen: Click to add variable. - Move the cursor to this message on the x-axis. - Select x. - Move the cursor to this message on the y-axis. The message may not appear right away until the cursor gets close to it. - Select y by using the down arrow of the Nav Pad. 3

4 Find the linear regression line which is the calculator s version of your line of best fit where you visually estimated the line of best fit. - Press Menu - Select 4: Analyze and press the right arrow of the Nav Pad - Select 6: Regression and press the right arrow of the Nav Pad - Select : Show Linear (mx + b) - Press Enter Write your function below. Write the calculator s function below. Compare this linear regression line and function to your line of best fit where you visually estimated the line of best fit and the function you developed. 4

5 Find the Pearson r. - Press Ctrl and the left arrow of the Nav Pad to get back to the Lists and Spreadsheets - Highlight the shaded area beneath Column C. - Press Menu - Select 4: Statistics and press the right arrow of the Nav Pad - Select : Stat Calculations and press the right arrow of the Nav Pad. - Select 3: Linear Regression (mx + b) - Press Enter 5

6 - Press the down arrow on the Nav Pad. - Use the down arrow on the Nav Pad and select x. - Press the down arrow on the Nav Pad. - Use the down arrow on the Nav Pad and select y. - F is fine. - is fine for frequency list. - Leave Category List alone. - Leave Include Categories alone. - Leave st result column alone. - The cursor is now on OK. Scroll down to find the Pearson r. Round the Pearson r to the nearest hundredth. 6

7 Graph the Pearson r on the number line below. - - Now for the remaining data sets, all you have to do is change the data in the lists and spreadsheets screen. The regression line, function and Pearson r will change automatically. - Use the left arrow and up arrow of the Nav Pad and put the cursor beneath the first column in row. - Enter the x values from data set b into the first column. Just type over the old values. - Press Enter after each data entry. - Use the right arrow and up arrow of the Nav Pad and put the cursor beneath the second column in row. - Enter the y values from data set b into the second column. Just type over the old values. - Press Enter after each data entry - Use the right arrow of the Nav Pad to go to the new Pearson r. - Press Ctrl right arrow on the Nav Pad to see the new function and linear regression line. 7

8 b.) Your function: Calculator s function: Pearson r: Graph the Pearson r on the number line below. - - c.) Your function: Calculator s function: Pearson r: Graph the Pearson r on the number line below

9 d.) Your function: Calculator s function: Pearson r: Graph the Pearson r on the number line below. e.) Your function: Calculator s function: Pearson r: Graph the Pearson r on the number line below

10 f.) Your function: Calculator s function: Pearson r: Graph the Pearson r on the number line below. - -