Question

Consider the following time series data.

Week	1	2	3	4	5	6
Value	20	13	15	10	17	13

Using the naïve method (most recent value) as the forecast for the next week, compute the following measures of forecast accuracy.

(c)	Mean absolute percentage error
	If required, round your intermediate calculations and final answer to two decimal places.

Answer 1

Time period	Actual Value(A)	Moving avg. Forecast(F)	Forecast error E=|A-F|	Squared Forecast Error	|A-F|A
1	20
2	13	20	7	49	0.5385
3	15	13	2	4	0.1333
4	10	15	5	25	0.5000
5	17	10	7	49	0.4118
6	13	17	4	16	0.3077
7		13
		Total	25	143	1.89
		Average	5.00	28.60	37.83%
			MAD	MSE	MAPE
a) mean absolute error=			5.00
b) mean squared error =			28.60
c) mean absolute % error=			37.83%
d) forecast for week 7 =			13