Question

Calculate the MAPE for your forecast series using the values for year 2 through year 7.

Year	CP	Forecast
1	$12.96
2	$14.31	$12.96
3	$15.34	$14.31
4	$15.49	$15.34
5	$15.70	$15.49
6	$16.00	$15.70
7	$15.62	$16.00
8		$15.62

Answer 1

Calculation of MAPE :

CP	Forecast	CP-Forcast/CP*100
14.31	12.96	14.31-12.96/14.31*100=9.43%
15.34	14.31	15.34-14.31/15.34*100=6.71%
15.49	15.34	15.49-15.34/15.49*100=0.97%
15.70	15.49	15.70-15.49/15.70*100=1.34%
16.00	15.70	16-15.7/16*100=1.87%
15.62	16.00	15.62-16/15.62*100=2.43%
	Total	22.75%

*While calculating CP-Forecast/CP*100, take the ABSOLUTE values.That means in the seventh year even 15.62-16/15.62*100 is -2.43% we have to consider as 2.43%

MAPE = 1/n*Total of (CP-Forcast/CP)*100

n =6 years

MAPE = 1/6*22.75%

= 3.79%