If the Actual Value of a Time Series at Time $\frac{\sum_{t=1}^{n}\left|A_{t}-F_{t}\right|}{n}$

Multiple Choice

If the actual value of a time series at time t and the forecast value for time t is denoted by At and Ft respectively, then the formula for the mean absolute deviation over a range of forecasted values is ________.

A) MAD = $\frac{\sum_{t=1}^{n}\left|A_{t}-F_{t}\right|}{n}$

B) MAD = $\frac { \sum _ { t = 1 } ^ { n } \left( \left| A _ { t } - F _ { t } \right| \right) ^ { 2 } } { n }$

C) MAD = $\frac { \sum _ { t = 1 } ^ { n } \sqrt { \left| A _ { t } - F \right| } } { n }$

D) MAD = $\frac { \sum _ { t = 1 } ^ { n } \left| \frac { A _ { t } - F _ { t } } { 2 } \right| } { n }$