The owner of Original Italian Pizza restaurant chain wants to understand which variable most strongly influences the sales of his specialty deep-dish pizza. He has gathered data on the monthly sales of deep-dish pizzas at his restaurants and observations on other potentially relevant variables for each of several outlets in central Indiana. These data is provided given below. Estimate a simple linear regression equation between the quantity sold (Y) and each of the following candidates for the best explanatory variable: average price of deep-dish pizzas, monthly advertising expenditures, and disposable income per household in the areas surrounding the outlets. Which variable is most strongly associated with the number of pizzas sold? Explain your choice. Outlet Number Quantity Sold Average Price Monthly Advertising Expenditures Disposable Income per Household
1 85,300 $10.14 $64,800 $42,100
2 40,500 $10.88 $42,800 $38,300
3 61,800 $12.33 $58,600 $41,000
4 50,800 $12.70 $46,500 $43,300
5 60,600 $12.29 $50,700 $44,000
6 79,400 $9.79 $60,100 $41,200
7 71,400 $11.26 $55,600 $41,700
8 70,700 $11.23 $57,900 $43,600
9 55,600 $11.97 $52,100 $39,900
10 70,900 $12.07 $60,700 $44,800
11 77,200 $10.68 $64,400 $41,800
12 63,200 $12.49 $55,600 $44,200
13 71,100 $12.36 $60,900 $40,100
14 55,500 $9.96 $47,200 $39,100
15 42,100 $11.77 $46,100 $38,000