Cellulon, a manufacturer of home insulation, wants to develop guidelines for builders and consumers on how the thickness of the insulation in the attic of a home and the outdoor temperature affect natural gas consumption. in the laboratory, it varied the insulation thickness and temperature. a few of the findings are: monthly natural gas consumption thickness of insulation outdoor temps(f)(y) x_1 x_230.3 6 4026.9 12 4022.1 8 49on the basis of the sample results, the regression equation is: ŷ= 62.65 - 1.86x_1 - 0.52x_2a. how much natural gas can homeowners expect to use per month if they install 6 inches of insulation and the outdoor temperature is 40°f? b. what effect would installing 7 inches of insulation instead of 6 have on the monthly natural gas consumption (assuming the outdoor temp remains at 40°f? )c. why are the regression coefficients b_1 and b_2 negative? is this logical?