3. Covid Co. has the following monthly sales in 2020: Sales (000 units) Month Sales (000 units) Month January 567 July 522 February 231 August 752 March 610 September 645 April 309 October 229 May 736 November 456 June 380 December 700 a. Plot the monthly data. b. Forecast September sales volume using the following: 1) A linear regression 2) A 6-month moving average 3) Exponential smoothing with a smoothing constant equal to 0.20 and assuming a March forecast of 600,000. 4) The nave approach 5) A weighted average using 0.7 for Dec, 0.2 for November and 0.1 for October. 6) Correlation c. Which method in b) is the MOST appropriate method to be used? Why