Curie is the new manager of the materials storeroom for Walker Manufacturing. Maeve has been asked to estimate future monthly purchase costs for part #696, used in two of Walker's products. Maeve has purchase cost and quantity data for the past 9 months as follows:

Month	Cost of Purchase	Quantity Purchased
January	$12,450	2,690 parts
February	12,660	2,820
March	17,314	4,080
April	16,055	3,777
May	13,170	3,001
June	14,022	3,365
July	15,278	3,633
August	10,094	2,275
September	14,980	3,522

Estimated monthly purchases for this part based on expected demand of the two products for the rest of the year are as follows:\

Month	Purchase Quantity Expected
October	3,330 parts
November	3,710
December	3,080

Requirements

1.	The computer in Maeve's office is down, and Maeve has been asked to immediately provide an equation to estimate the future purchase cost for part #696. Maeve grabs a calculator and uses the high-low method to estimate a cost equation. What equation does she get? ( ) = ( ) + ( ( ) ( ) )
2.	Using the equation from requirement 1, calculate the future expected purchase costs for each of the last 3 months of the year.
3.	After a few hours Maeve's computer is fixed. Maeve uses the first 9 months of data and regression analysis to estimate the relationship between the quantity purchased and purchase costs of part #696. The regression line Maeve obtains is as follows:y = $1,987.5 + 3.71X Evaluate the regression line using the criteria of economic plausibility, goodness of fit, and significance of the independent variable. Compare the regression equation to the equation based on the high-low method. Which is a better fit? Why?
4.	Use the regression results to calculate the expected purchase costs for October, November, and December. Compare the expected purchase costs to the expected purchase costs calculated using the high-low method in requirement 2. Comment on your results.