Chapter 10, Problem 10.37P

High-low method; regression analysis. (CIMA, adapted) Catherine McCarthy, sales manager of Baxter Arenas, is checking to see if there is any relationship between promotional costs and ticket revenues at the sports stadium. She obtains the following data for the past 9 months:

Month	Ticket Revenues	Promotional Costs
April	$200,000	$52,000
May	270,000	65,000
June	320,000	80,000
July	480,000	90,000
August	430,000	100,000
September	450,000	110,000
October	540,000	120,000
November	670,000	180,000
December	751,000	197,000

She estimates the following regression equation:

  $\text{Ticket}\text{revenues}=\$65,583+(\$3.54\times \text{Promotional}\text{costs})$

1. 1. Plot the relationship between promotional costs and ticket revenues. Also draw the regression line and evaluate it using the criteria of economic plausibility, goodness of fit, and slope of the regression line.
2. 2. Use the high-low method to compute the function relating promotional costs and revenues.
3. 3. Using (a) the regression equation and (b) the high-low equation, what is the increase in revenues for each $10,000 spent on promotional costs within the relevant range? Which method should Catherine use to predict the effect of promotional costs on ticket revenues? Explain briefly.