11.50 Multiple regression model for total TEQ. Dioxins and furans are other classes of chemicals that can cause undesirable health effects similar to those caused by PCB. The three types of chemicals are combined using toxic equivalent scores (TEQs), which attempt to measure the health effects on a common scale. The PCB data file contains TEQs for PCB, dioxins, and furans. The variables are called TEQPCB, TEQDIOXIN, and TEQFURAN. The data file also includes the total TEQ, defined to be the sum of these three variables.

  1. (a) Consider using a multiple regression to predict TEQ using the three components TEQPCB, TEQDIOXIN, and TEQFURAN as explanatory variables. Write the multiple regression model in the form

  3. Give numerical values for the parameters β0, β1, β2, and β3.

  4. (b) The multiple regression model assumes that the ϵ’s are Normal with mean zero and standard deviation σ. What is the numerical value of σ?

  5. (c) Use software to run this regression and summarize the results.