hello could u explain to me how did u do regression

Jayne reminded Ethan that maintenance of the machines is required for the silk-screen process. In addition, Ethan realizes that he must consider the cost of utilities. The building Ethan wants to rent is roughly the same size as the building occupied by Shirts and More. In addition, Shirts and More sells approximately the same number of shirts Ethan plans to sell in his store. Therefore, Ethan is confident that the maintenance and utility costs for his shop will be comparable to the maintenance and utility costs for Shirts and More as below. Ethan will use the regression method to estimate variable and fixed costs for the purpose of budgeting. Shirts Sold Maintenance Cost Utility Cost January 1,810 $1,630 $1,150 February 2,110 1.720 1,158 March 2,630 1,740 1,161 April 3,250 1,780 1,211 May 5,000 1.912 1,485 June 5,300 1,966 1,502 July 3,920 1,805 1,278 August 2,100 1,725 1,143 September 8,000 2, 120 1,688 October 6,810 2.030 1,630 November 6,020 2,014 1,498 December 8,700 2.240 1,740 (Note: When estimating maintenance and utility costs, input data on a worksheet and use Excel functions to estimate the slope and the intercept. When you budget maintenance and utility costs, you should use formulas linked to the estimates of slope and intercept, and related quantity of shirts, instead of inputting numbers by hand. Use Excel to display the total costs to the whole dollar.)