The following table shows the relationship between the speed of a car (mph) and the average stopping distance (feet) after the brakes are applied.
Speed (mph)
0
10
20
30
40
50
60
70
Distance (ft)
0
20
50
95
150
220
300
400
The least-squares regression equation for predicting stopping distance from speed is:
y = -44.2 + 5.67x
a) State which variable is the explanatory variable and which variable is the response variable.
A. Distance is the explanatory variable and speed is the response variable.
B. Speed is the explanatory variable and distance is the response variable.
b) What is the predicted stopping distance for a car going 60 mph?
feet (round to the nearest whole integer)
c) Calculate the residual for the car going 60 mph.
feet (round to the nearest whole integer)
d) Pick the correct interpretation for the slope.
A. For every additional 1 mph in speed, the stopping distance increases by 5.67 feet.
B. For every additional 1 mph in speed, the stopping distance increases by 44.2 feet.
C. For every additional 5.67 mph, the stopping distance increases by 44.2 feet.
D. For every additional 1 foot in stopping distance, the speed increases by 5.67 mph.
e) If a car's speed increases by 15 mph, how much would the predicted stopping distance increase?
feet (round to the nearest whole integer)