Refer to the U.S. Army Corps of Engineers data on fish contaminated from the toxic discharges of a chemical plant located on the banks of the Tennessee River in Alabama. In Exercise 11.26 you fit the first-order model E(y) = β_o + β₁x₁ + β₂x₂ + β₃x₃, where y = DDT level in captured fish, x₁ = miles captured upstream, x₂ = fish length, and x₃ = fish weight. Conduct a complete residual analysis for the model. Do you recommend that any model modifications be made? Explain.

Data from Exercise 11.26

Refer to the U.S. Army Corps of Engineers data on fish contaminated from the toxic discharges of a chemical plant located on the banks of the Tennessee River in Alabama. Recall that the engineers measured the length (in centimeters), weight (in grams), and DDT level (in parts per million) for 144 captured fish. In addition, the number of miles upstream from the river was recorded. The data are saved in the DDT file.

Transcribed Image Text:

DDT River Mile species Length weight DDT FC 5 CHANNELCATFISH 42.5 732 10.00 FC 5 CHANNELCATFISH 44.0 795 16.00 FC 5 CHANNELCATFISH 41.5 547 23.00 FC 5 CHANNELCATFISH 39.0 465 21.00 FC 5 CHANNELCATFISH 50.5 1252 50.00 TR 345 LARGEMOUTHBASS 23.5 358 2.00 TR 345 LARGEMOUTHBASS 30.0 856 2.20 TR 345 LARGEMOUTHBASS 29.0 793 7.40 TR 345 LARGEMOUTHBASS 17.5 173 0.35 TR 345 LARGEMOUTHBASS 36.0 1433 1.90 .... ....