Question

Consider the following time series data.

Week	1	2	3	4	5	6
Value	19	14	16	11	18	15

Using the naive method (most recent value) as the forecast for the next week, compute the following measures of forecast accuracy. Round the intermediate calculations to two decimal places.

1. Mean absolute error (to 1 decimal).
   
   
2. Mean squared error (to 1 decimal).
   
   
3. Mean absolute percentage error (to 2 decimals).
   %
   
4. What is the forecast for week 7 (to the nearest whole number)?
   

Answer 1

Time period	Actual Value(A)	Moving avg. Forecast(F)	Forecast error E=|A-F|	Squared Forecast Error	|A-F|A
1	19
2	14	19	5	25	0.3571
3	16	14	2	4	0.1250
4	11	16	5	25	0.4545
5	18	11	7	49	0.3889
6	15	18	3	9	0.2000
7		15
		Total	22	112	1.53
		Average	4.40	22.40	30.51%
			MAD	MSE	MAPE

a)

Mean absolute error =4.40

b)

Mean squared error =22.40

c)

Mean absolute percentage error =30.5%

d)

forecast for week 7 =15