Question 4:

1. The Marino Company in Ventura County, southern California sells swimming pool equipment. The sales for swimming pool motors in southern California over the last 12 months is given in Table Q4(a). Forecast the demand from March to December of the current year using the following forecasting models. Use excel for the tabulation.

1. Three-month simple moving average;
2. Three-month weighted moving average. Use 0.7, 0.2, and 0.1 for the weights, with

0.7 for the most recent period, and 0.1 for the oldest period.

3. Simple linear regression;
4. Determine the MAD, and SE for all the models, and choose which model is most appropriate.

Table Q4(a) Marino Company Sales of Swimming pool motors

Month	Quantity (units)
January	11,959
February	14,664
March	16,434
April	10,070
May	15,652
June	17,465
July	11,844
August	14,963
September	17,744
October	12,080
November	14,063
December	16,445