Page 480 - Algebra 1

7. Find the linear regression for the scatter plot. Press and the key to highlight the CALC menu. Select 4:LinReg(ax+b).
8. Set the parameters for the linear regression. Press and choose 1:L1. Then press
and choose 2:L2.
9. To view the line of best fit with the scatter plot, press and
the key to highlight Y-VARS. Then press the destination for the equation.
10. Press . To write the equation of the line of best fit, the values of a and b are 0.036 and 1.236, respectively. The equation for the line of best fit is y = 0.036x + 1.236.
11. Press to view the line of best fit with the scatter plot.
12. Predict the value of y when x = 11. Since
x = 11 is outside the viewing window, press
and the key and type 11.
13. Press and select 1:value. Type 11 and press . When x = 11, the value of
y is 1.632.
Therefore, according to the line of best fit, there would
be about 1.632 billion movie admissions in the year 2004.
Lab Practice
twice to select Y1 as
The table gives solar energy cell capacity y in megawatts for x years after 1989. Use a graphing calculator to create a scatter plot and to graph the line of best fit for the data. What is an equation for the line of best fit? Use the model to predict the solar-energy cell capacity in 1996 (x = 7).
Year(x) 1 2 3 4 5 6 Capacity (y) 13.8 14.9 15.6 21.0 26.1 31.1
Lab 7 465