Question $15$

A forecasting method has produced the following over the past five months. What is the mean absolute deviation?

$$

Actual

Forecast

$10$

$11$

$8$

$10$

$10$

$8$

$6$

$6$

$9$

$8$

$$

A$.$

$-0\mathrm{.}2$

B$.$

$-1\mathrm{.}0$

C$.$

$0\mathrm{.}0$

D$.$

$1\mathrm{.}2$

E$.$

$8\mathrm{.}6$