One research department at Superior has been asked to develop some guidelines regarding heating costs for single-family homes in Thunder Bay. Three variables are thought to relate to the heating costs: (1) X1: the mean daily outside temperature, (2) X2: the number of centimetres of insulation in the attic, and (3) X3: the age of the furnace. To investigate, Superior's research department selected a random sample of 20 recently sold homes. They determined the cost to heat the home last January, as well as the January outside temperature in Thunder Bay, the number of centimeters of insulation in the attic, and the age of the fumace. Based on the sampling data the following regression model is obtained: 3/ = 14-0. 3187 12.3168X1 4-. 10131X2 + 8. 526762113 a) Please explain this equation by using the relevant regression analysis. b) If the mean outside temperature for the month is -18C, with 7.5 cm of insulation, and the fumace is 5 years old, what is the cost to heat the home