6-3A - High-Low Method, Scattergraph, Least-squares Regression Bill's Burger Restaurant has noticed a strong correlation between the number of customers served and the monthly maintenance costs: Required: a.) Using the high-low method, estimate the cost formula (write it in y=mx+b format). i. Using your answer from part a.) above, assuming in July the company expects to have 2,000 customers, what will be the company's estimated maintenance cost. b.) Using the scattergraph method, estimate the cost formula. c.) Using the least squares regression method, estimate the cost formula. d.) Are there any factors other than the number of customers that may contribute to a variation in maintenance cost