Researchers studying how a car's Fuel Efficiency varies with its Speed drove a compact car 200 miles at various speeds on a test track. Their data are shown in the table.
|
Speed (mph)
|
35
|
40
|
45
|
50
|
55
|
60
|
65
|
70
|
75
|
|
Fuel Eff. (mpg)
|
25.9
|
27.7
|
28.5
|
29.5
|
29.2
|
27.4
|
26.4
|
24.2
|
22.8
|
Create a linear model for this relationship and report any concerns you may have about the model.