17. The article Characterization of Highway Runoff in Austin, Texas, Area (J. Environ. Engrg., 1998:

131—137) gave a scatter plot, along with the least squares line, of x  rainfall volume (m3) and y 
runoff volume (m3) for a particular location. The accompanying values were read from the plot.
x 5 12 14 17 23 30 40 47 y 4 10 13 15 15 25 27 46 x 55 67 72 81 96 112 127 y 38 46 53 70 82 99 100

a. Does a scatter plot of the data support the use of the simple linear regression model?

b. Calculate point estimates of the slope and intercept of the population regression line.

c. Calculate a point estimate of the true average runoff volume when rainfall volume is 50.

d. Calculate a point estimate of the standard deviation s.

e. What proportion of the observed variation in runoff volume can be attributed to the simple linear regression relationship between runoff and rainfall?