OI Problem 1. National Scan, Inc., sells radio frequency inventory tags. Monthly sales for a seven-month period were as follows: Month Feb. Mar. Apr. May Jun. Jul. Aug. Sales (000 units) 19 18 15 20 18 22 20 a. Plot the monthly data on a sheet of graph paper. b. Forecast September sales volume using each of the following: (1) The naive approach. (2) A five month moving average. (3) A weighted average using .60 for August, .30 for July, and .10 for June. (4) Exponential smoothing with a smoothing constant equal to 20, assuming a a March forecast of 19(000). (5) A linear trend equation