Multiple regression output from Minitab for the PAH data of Exercise 53 in the previous...

Multiple regression output from Minitab for the PAH data of Exercise 53 in the previous section included the following information:

What does this suggest about the appropriateness of using the previously given fitted equation as a basis for inferences? The investigators actually eliminated observation #7 and re-regressed. Does this make sense?

Reference exercise 53

Snowpacks contain a wide spectrum of pollutants that may represent environmental hazards. The article “Atmospheric PAH Deposition: Deposition Velocities and Washout Ratios” (J. of Environmental Engineering, 2002: 186–195) focused on the deposition of polyaromatic hydrocarbons. The authors proposed a multiple regression model for relating deposition over a specified time period (y, in mg/m2) to two rather complicated predictors x₁ (mg-sec/m³) and x₂ (mg/m²), defined in terms of PAH air concentrations for various species, total time, and total amount of precipitation. Here is data on the species fluoranthene and corresponding Minitab output:

Formulate questions and perform appropriate analyses to draw conclusions.