Find the Average Value of the Function $f ( x ) = x e ^ { - x / 3 }$

Multiple Choice

Find the average value of the function $f ( x ) = x e ^ { - x / 3 }$ over the interval from 0 to 4.Round to two decimal places.

A) 0.87
B) 3.46
C) 10.86
D) 7.79