Consider the following time series data. The time series appears to be relatively stable, without trend, seasonal, or cyclical effects. If the smoothing constant is assumed to be 0.6, and setting F1 and F2 = A1, what is the mean absolute deviation for the given data?

Period	Actual value
Period 1	10
Period 2	11
Period 3	9
Period 4	12
Period 5	13
Period 6	11

• A.

  0.41

• B.

  8.13

• C.

  1.35

• D.

  2.48