a. Use a graphing calculator to find the equation of the line of best fit for the data below. Let x=8 represent 1998, x=9 represent 1999, and so on. b. What is the slope of the line of best fit? What does the slope mean in terms of the number of computer and video game units sold? c. What is the y-intercept of the line of best fit? What does the y-intercept mean in terms of the number of computer and viedo game units sold?

a. Use a graphing calculator to find the equation of the line of best fit for the data below. Let x=8 represent 1998, x=9 represent 1999, and so on. b. What is the slope of the line of best fit? What does the slope mean in terms of the number of computer and video game units sold? c. What is the y-intercept of the line of best fit? What does the y-intercept mean in terms of the number of computer and viedo game units sold?

Question
Linear equations and graphs
asked 2021-01-22
a. Use a graphing calculator to find the equation of the line of best fit for the data below. Let x=8 represent 1998, x=9 represent 1999, and so on.
b. What is the slope of the line of best fit? What does the slope mean in terms of the number of computer and video game units sold?
c. What is the y-intercept of the line of best fit? What does the y-intercept mean in terms of the number of computer and viedo game units sold?

Answers (1)

2021-01-23
a. Input the x-values 8 to 17 under L1 in your graphing calculator since 1998 is represented by x=8, 1999 is represented by x=9, etc. Then input the corresponding yy-coordinates under L2. Then use the LinReg feature to find the equation for the line of best fit. The calculator gives a slope of about 10.53 and a y-intercept of about 88.21 so the equation for the line of best fit is y=10.53x+88.21. b. The slope of the line of best fit is about 10.53. Since yy is the unit sales, in millions, and x is the year, the slope has units of unit sales (in millions) per year. The slope of 10.53 then means that unit sales are increasing by about 10.53 million per year. c. The yy-intercept is about 88.21. The yy-intercept occurs when x=0x=0 which represents the year 1990. The yy-intercept of 88.21 then means that unit sales were about 88.21 million in 1990.
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