To investigate the relationship between amount of sales y (in thousands of dollars) and the amount x (in hundreds of dollars) spent on advertising, a marketing researcher chooses eight cities of approximately equal populations and spends differing amounts on advertising in each city. The sales y and the amount x spent on advertising are recorded for each city. From the data the least squares prediction line is: = 24.45 + 2.38x.
Interpret the slope of the least squares line.
(A) For each additional hundred dollars spent on advertising, sales are predicted to increase by $2,380.
(B) If no money is spent on advertising, sales are predicted to be $24.45.
(C) For each additional hundred dollars spent on advertising, sales are predicted to increase by $24,452.
(D) For each additional $1000 dollars in sales, the amount spent on advertising is predicted to increase by $238.