Heller Company manufactures lawn mowers and related lawn equipment. The managers believe the quantity of lawn mowers sold depends on the price of the mower and the price of a competitor's mower. The worksheet entitled "Mowers" in the hw4.xlsx contains data on Heller's price, the competitor's price and the number of units sold. Use the data to estimate a multiple linear regression model, with the number of units sold as the dependent variable and the two prices as the independent variables. Based on your model, if Heller's price increased by $1 while the competitor's price remained the same, how much do you estimate that the number of units sold would change? (If the number of units goes down, answer with a negative number; otherwise answer with a positive number) Report your answer as an integer.
Quantity Sold Competitor's price Heller's price
102,000 120 100
100,000 140 110
120,000 190 90
77,000 130 150
46,000 155 210
93,000 175 150
26,000 125 250
69,000 145 270
65,000 180 300
85,000 150 250