The average temperature (in degrees Fahrenheit) and average wind speed (in miles per hour) were recorded for 365 consecutive days at Chicago’s O’Hare International Airport. Here is computer output for a regression of y = average wind speed on x = average temperature:

Summary of Fit

RSquare ..................................... 0.047874
RSquare Adj .............................. 0.045251
Root Mean Square Error ......... 3.655950
Mean of Response ................... 9.826027
Observations (or Sum Wgts) ............ 365

Parameter Estimates

a. Calculate and interpret the residual for the day where the average temperature was 42°F and the average wind speed was 2.2 mph.

b. Interpret the slope.

c. By about how much do the actual average wind speeds typically vary from the values predicted by the least-squares regression line with x = average temperature?

d. What percent of the variability in average wind speed is accounted for by the least-squares regression line with x = average temperature?

Prob> |t|