The number of fishing rods selling each day are given below. Perform analyses of the time series to determine which model should be used for forecasting.
(a) 3 day moving average analysis
(b) 4 day moving average analysis
(c) 3 day weighted moving average analysis with weights w1=0.2, w2=0.3 and w3=0.5 with w1 on the oldest data
(d) exponential smoothing analysis with a = 0.3.
(e) Which model provides a better fit of the data? (3 marks) (f) Forecast day 13 sales of fishing rods using the model chosen in part(e).
day rod sold
1 60
2 70
3 110
4 80
5 70
6 85
7 115
8 105
9 65
10 75
11 95
12 85
2.Perform a Trend and Seasonal analysis with the following data. Include the trend formula and the multiplicative indices for the seasons. Using the model forecast sales for the next year (all 4 seasons of year 4).
year season sales
1 sp 140
1 su 50
1 w 130
1 f 520
2 sp 200
2 su 110
2 w 190
2 f 550
3 sp 260
3 su 220
3 w 210
3 f 570