=+5.37 ● The following data on x 5 soil depth (in centimeters) and y 5 percentage of montmorillonite in the soil were taken from a scatterplot in the paper “Ancient Maya Drained Field Agriculture: Its Possible Application Today in the New River Floodplain, Belize, C.A.” (Agricultural Ecosystems and Environment [1984]: 67–84):

x 40 50 60 70 80 90 100 y 58 34 32 30 28 27 22

a. Draw a scatterplot of y versus x.

b. The equation of the least-squares line is 5 64.50 2 0.45x. Draw this line on your scatterplot. Do there appear to be any large residuals?