As a science project, Shelley is studying the relationship of car mileage (in miles per gallon) and speed (in miles per hour). The table shows the data Shelley gathered using her family's
vehide. Use a graphing calculator to create a scatter plot of the data, find a linear regression
model, and graph the model. Then use the model to predict the gas mileage of the car at a
speed of 20 miles per hour.
30
40
50
Speed (mi/h)
Mileage (mi/gal)
34.0
335
31.5
29.0
27.5
The function is modeled by the equation f(x) = -0.175x+39.5.
1. Using the given function, what would Shelly's gas mileage
be if she drove 75 miles per hour?