Question

The following table shows the bimonthly tequila sales in gallons of a retail store. Year Bimester 1 1 2 3 4 5 6 2 1 2 3 2011 223 272 445 560 612 467 247 343 464 680 711 610 324 404 677 858 895 664 4 5 6 3 1 2 3 4 5 6 a) Make a time series diagram. What do you observe? What type of series is it? Explain. b) Identify the forecast model to use and prepare the best forecast for the entire 4 year. and set the error associated with it.

Answer 1

(a) The graph is:

Plot 1000 900 800 700 600 500 400 300 200 100 0 0 5 10 15 20

There is a horizontal pattern in the data with seasonality. Thus, this is a seasonal model.

(b) Forecasts

Period	Forecast
19	370.05
20	477.36
21	710.37
22	948.99
23	1016.91
24	816.77

The plot is:

Time Series Decomposition Plot for C1 Multiplicative Model 1100 1000 Variable Actual Fits Trend Forecasts 900 800 Accuracy Measures MAPE 4.007 MAD 20.810 MSD 793.833 700 C1 600 500 400 444 300 200 4 8 10 16 18 20 22 24 N 12 14 Index