Question: Interstate 90 is the longest of the east-west U.S. interstate highways with its 3,112 miles stretching from Boston, MA at I-93 on the eastern end to Seattle WA at the Kingdome on the western end. It travels across 13 northern states; the number of miles and number of intersections in each of those states is listed below.

a. Construct a scatter diagram of the data.

b. Find the equation for the line of best fit using x= miles and y=intersections.

c. Using the equation found in part (b), estimate the average number of intersections per mile along I-90.

d. Find a 95% confidence interval for β₁.

e. Explain the meaning of the interval found in part d.