Sales of walking shorts at Hugo’s Department Store in downtown Rolla appear to exhibit a seasonal pattern. The proprietor of the store, Wally Hugo, has kept careful records of the sales of several of his popular items, including walking shorts. During the past two years the monthly sales of the shorts have been Y ear 1 Y ear 2 Y ear 1 Y ear 2 Jan. 12 16 July 112 130 Feb. 18 14 Aug. 90 83 March 36 46 Sep. 66 52 April 53 48 Oct. 45 49 May 79 88 Nov. 23 14 June 134 160 Dec. 21 26 Assuming no trend in shorts sales over the two years, obtain estimates for the monthly seasonal factors.