Question

Consider the following time series data.

Week	1	2	3	4	5	6
Value	20	12	15	11	19	15

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

Mean absolute error. Round your answer to one decimal place.


________

Mean squared error. Round your answer to one decimal place.

_______

Mean absolute percentage error. Round your answer to two decimal places.

_______

What is the forecast for week 7? Round your answer to the nearest whole number.

_________

Answer 1

Week	Value [Time]	Forecast	Error	Absolute Error	Square Error	% error	Absolute % error
1	20					[Error/Time]
2	12	20	12-20 = -8	8	64	-67%	67%
3	15	12	15-12 = 3	3	9	20%	20%
4	11	15	11-15 = -4	4	16	-36%	36%
5	19	11	19-11 = 8	8	64	42%	42%
6	15	19	15-19 = -4	4	16	-27%	27%
			TOTAL	27	169	-68%	192%
		0
	Mean absolute error = Absolute Error/n
			= 27/5
			5.4
	Mean Square Error= Square Absolute Error /n
			= 169/5
			33.8
	Mean absolute % error = Absolute % error /n
			= 192%/5
			38.40%
	What is the forecast for week 7 = Actual value for week 6 = 14