17: A forecasting method has produced the following data over the past 6 months.

What is the MAD at the end of 6 months?

Month Actual Forecast Error |Error|
1 10 9 1 1 2 8 10 − 2 2 3 10 8 2 2 4 6 6 0 0 5 9 8 1 1 6 11 12