Sales of industrial vaccum cleaners at R. Lowenthal supply Co. over the past thirteen months are as follows:
Sales ( $1,000s)/ month 11- Jan. 14- Feb. 16- march 10-april 15-may 17-june 11-july 14-august 17-sept. 12-oct. 14-nov. 16-dec. 11-jan.
i) using the moving average with 3 periods, find demand for vaccum cleaners for next feb.
ii) using the weighted moving average with 3 periods, find demand for vaccum cleaners for February. Use 3,2, and 1 for weights of most recent, second most recent, and third most recent periods, respectively. For instance, if you were predicting demand for Feb., November would have the weight of 1, December would have the weight of 2, and January would have the weight of 3.
iii) Estimate accuracy of each of the methods.
iv) What other factors might R. Lowenthal consider in predicting sales.