Taxi Tires a Taxi Company Monitoring the Safety of Its $= 36 - 0.6$

Essay

Taxi tires A taxi company monitoring the safety of its cabs kept track of the number of
miles tires had been driven (in thousands) and the depth of the tread remaining (in mm).
Their data are displayed in the scatterplot. They found the equation of the least squares regression line to be tread $= 36 - 0.6$ miles, with $r ^ { 2 } = 0.74$ .


a. Draw the line of best fit on the graph. (Show your method clearly.)
b. What is the explanatory variable?
c. The correlation $r =$
d. Describe the association in context.
e. Explain (in context) what the slope of the line means.
f. Explain (in context) what the $y$ -intercept of the line means.
g. Explain (in context) what $R ^ { 2 }$ means.
h. In this context, what does a negative residual mean?