Page 479 - Algebra 1

7L A B
Finding the Line of Best Fit
Graphing Calculator Lab (Use with Lesson 71)
A graphing calculator is often the easiest and most accurate method for making a scatter plot from a data set and then finding the equation of the line of best fit.
The following table gives the total number y in billions of movie admissions for x years after 1993.
Find a line of best fit for the data. According to the model, about how many billion movie admissions were there in 2004 (x = 11)?
1. Press and choose 1:Edit. Clear any old data by pressing the key until the list name is selected. Press and then .
2. Enter the x-values as L1. Use the key to move to the next column and enter the
y-values as L2.
3. Press and select 1:Plot1... to
open the plot setup menu.
4. Press to turn Plot1 On. Then press the key once and then to select the
first Type.
5. The default settings for Xlist: and Ylist: are L1 and L2, respectively. If these are not the current settings, then move the cursor next to Xlist:. Press . Select the list of independent variables, 1:L1. To change the Ylist: setting, press and select 2:L2, the list of dependent variables.
6. Create a scatter plot by pressing and selecting 9:ZoomStat.
Year (x)
1
2
3
4
5
6
7
8
9
10
Admissions (y)
1.29
1.26
1.34
1.39
1.48
1.47
1.42
1.49
1.63
1.57
Graphing Calculator Tip
For help with entering data into a list, see the graphing calculator keystrokes in Graphing Calculator Lab 4 on page 343.
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464 Saxon Algebra 1