An article gave a scatter plot along with the least squares line ofx= rainfall volume (m³) andy= runoffvolume (m³) for a particular location. The accompanying values were read from the plot

x 6 12 14 17 23 30 40 50 55 67 72 80 96 112 127

y 4 10 13 14 15 25 27 46 38 46 53 73 82 99 102

(b) Calculate point estimates of the slope and intercept of the population regression line. (Round your answers to five decimal places.)

slope =

intercept=

(c) Calculate a point estimate of the true average runoff volume when rainfall volume is47. (Round your answer to four decimal places.)

=m³

(d) Calculate a point estimate of the standard deviation. (Round your answer to two decimal places.)

=m³

(e) What proportion of the observed variation in runoff volume can be attributed to the simple linear regression relationship between runoff and rainfall? (Round your answer to four decimal places.)