excel only

Johnson motor products provides engines for commercial lawnmowers. Sales for the last six years are shown below. Date Sales (1000's) Six years ago 36 Five years ago 39 Four years ago 42 Three years ago 39 Two years ago 40 Last year 42 The company has asked you to determine whether a more accurate forecast of this year's can be made using a 'textbook' naive method or a three-period moving average method. Provide the appropriate evidence