http://www.ck12.org Chapter 7. Organizing and Displaying Data
Speed (m/h) 32 64 77 42 82 57 72
Fuel Efficiency (m/gal) 40 27 24 37 22 36 28a. Draw a scatter plot and a line of best fit using technology. What is the equation of the line of best fit?
b. What is the correlation coefficient and the coefficient of determination of the linear regression equation? Is the
linear regression equation a good fit for the data?
c. If a car were traveling at a speed of 47 m/h, estimate the fuel efficiency of the car.
d. If a car has a fuel efficiency of 29 m/gal, estimate the speed of the car.
Answer:
a.
From the following screen, the equation of the line of best fit is approximatelyy=− 0. 36 x+ 52 .6.
b. As can be seen in the screen in the answer to part a, the correlation coefficient is 0.9534582451, while the
coefficient of determination is 0.9090826251. This means that the linear regression equation is a moderately good
fit, but not a great fit, for the data.
c. Using the TI-83 to calculate the value, the fuel efficiency of a car traveling at a speed of 47 m/h would be
approximately 35 m.