5-60 pg. 216(check figure: high-low variable cost per unit = $6.30)(check figure: regression variable cost per unit = $8.04)2. Mac Renovations has been using the home's interior square feet for his exterior paint cost estimations.It was brought to his attention that adding a home's external openings might also be useful inpredicting painting cost estimations.The following data was gathered from the last 12 houses he had painted.House Costs Square Feet Openings1 $ 2,810 2,500 72 $ 3,742 3,150 123 $ 3,100 2,800 84 $ 3,150 2,850 85 $ 4,700 4,750 166 $ 3,225 2,950 87 $ 2,920 2,700 78 $ 2,836 2,550 69 $ 3,242 2,600 710 $ 4,112 3,700 1311 $ 3,210 2,650 712 $ 3,965 3,550 12Compute the total cost equation for the currently used interior square feet independent variableCompute the total cost equation when both interior square feet and external openings are used as independent variablesWhich total cost equation is more reliable and why?(check figure: linear regression fixed costs = $789.62)(check figure: multiple regression fixed costs = $1,385.74)