In a study nine tires of a particular brand were driven on a

In a study, nine tires of a particular brand were driven on a track under identical conditions. Each tire was driven a particular controlled distance (measured in thousands of miles), and afterward the tread depth was measured. Tread depth is measured in “mils.” Here, 1 mil is 0.001 inch. The least-squares regression line was computed, and added to a scatterplot of these data. On the plot, one data point is marked with an “X”.

The equation of the least-squares regression line is:

Tread Depth = 360.64 – 7.2x (thousands of miles)

Also, r² = 0.953.

The data value marked with “X” in the provided scatterplot has

A.

a negative value for the residual.

B.

a positive value for the residual.

C.

a zero value for the residual.

D.

a zero value for the correlation.

Solution

B.

a positive value for the residual.