Double-loop data for San Antonio is contained in the data file corresponding to Figure 3.1. a. Plot occupancy (Y) vs. speed (X). b. Fit a line to the data. c. Is the slope of the line significantly...

Double-loop data for San Antonio is contained in the data file corresponding to Figure 3.1. a. Plot occupancy (Y) vs. speed (X). b. Fit a line to the data. c. Is the slope of the line significantly different from zero? With what confidence level? d. What is a good estimate of the error standard deviation? How many degrees of freedom does it have? e. What is R2 ? f. Plot the residuals. Do any assumptions appear to be violated? g. Split the data into those observations with speeds less than 30 mph, and those with speeds equal to or greater than 30 mph. Fit both sets separately and compare the fits. What can you conclude?