An air conditioning and heating repair firm conducted a stud

An air conditioning and heating repair firm conducted a study to determine if the average outside temperature, thickness of the insulation, and age of the heating equipment could be used to predict the electric bill for a home during the winter months in Houston, Texas. The resulting regression equation was:

Y = 256.89 - 1.45X1 - 11.26X2 + 6.10X3, where Y = monthly cost, X1 = average temperature, X2 = insulation thickness, and X3 = age of heating equipment

If the average temperature is 68, insulation is 1 inches, and the age of the heating equipment is 6. What is the estimated monthly electric bill?

Solution

Answer

Y = 256.89 – 1.45(68) – 11.26(1) + 6.10(6)
Y = 256.89 – 98.6 – 11.26 + 36.6
Y = 147.03 + 36.6
Y = 183.63