Question

Consider the following time series data.

Week	1	2	3	4	5	6
Value	19	13	16	11	17	15

Using the average of all the historical data as a forecast for the next period, compute the following measures of forecast accuracy.

Round your answers to two decimal places.

a. Mean absolute error.

b. Mean squared error.

c. Mean absolute percentage error.
%

d. What is the forecast for week 7?

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	13	19	6	36	0.4615
3	16	16	0	0	0.0000
4	11	16	5	25	0.4545
5	17	14.75	2.25	5.0625	0.1324
6	15	15.2	0.2	0.04	0.0133
7		15.17
		Total	13.45	66.1025	1.06
		Average	2.69	13.22	21.24%
			MAD	MSE	MAPE

a)

Mean absolute error =2.69

b)

Mean squared error. =13.22

c)

Mean absolute percentage error =21.24%

d)

forecast for week 7 =15.17