Gator Beach Marts, a chain of convenience grocery stores in the Fort Lauderdale area, has store hours that fluctuate from month to month as the tourist trade in the community varies. The utility costs for one of the company's stores are listed below for the past six months. Total Hours of Total Utility Month Operation Cost January 450 $ 2,520 February 600 3,100 March 800 3,900 April 400 2,400 May 350 2,050 June 300 1,900 Required: 1-a. Use the high-low method to estimate the cost behavior for the store's utility costs. Express the cost behavior in formula form (Y =a + bX). 1-b. What is the variable utility cost per hour of operation? 3-a. Construct an Excel spreadsheet and use the Excel commands to perform a least-squares regression. Estimate the cost behavior for the store's utility cost. Express the cost behavior in formula form. 3-b. What is the variable utility cost per hour of operation? 4. During July, the store will be open 300 hours. Predict the store's total utility cost for July using each of the cost-estimation methods employed in requirements (1) and (3)