Two radon detectors were placed in different locations in the basement of a home. Each provided an hourly measurement of the radon concentration, in units of pCi/L. The data are presented in the following table.

a. Compute the least-squares line for predicting the radon concentration at location 2 from the concentration at location 1.

b. Plot the residuals versus the fitted values. Does the linear model seem appropriate?

c. Divide the data into two groups: points where R₁ < 4 in one group, points where R₁ ?? 4 in the other. Compute the least-squares line and the residual plot for each group. Does the line describe either group well? Which one?

d. Explain why it might be a good idea to fit a linear model to part of these data, and a nonlinear model to the other.

Transcribed Image Text:

R1 R2 R1 R2 R1 R2 R1 R2 1.2 1.3 1.2 3.4 2.0 4.0 2.6 5.5 3.6 3.5 1.5 1.6 2.0 4.0 2.7 5.8 3.6 1.3 3.6 2.1 4.3 2.7 5.9 3.9 1.3 1.7 3.6 2.1 4.3 2.8 6.0 4.0 1.5 1.7 3.7 2.1 4.4 2.9 6.0 4.2 1.5 1.7 3.8 2.2 4.4 3.0 6.1 4.4 1.6 1.8 3.8 2.2 4.7 3.1 6.2 4.4 2.0 1.8 3.8 2.3 4.7 3.2 6.5 4.4 2.0 1.9 3.9 2.3 4.8 3.2 6.6 4.4 2.4 1.9 3.9 2.4 4.8 3.5 6.9 4.7 2.9 1.9 3.9 2.4 4.9 3.5 7.0 4.8 3.0 2.0 3.9 2.4 5.4 3.5