Find the Expected Value of the Random Variable Whose Density $f ( x ) = \frac { 3 } { 8 } x ^ { 2 } , 0 \leq x \leq 2$

Multiple Choice

Find the expected value of the random variable whose density function is $f ( x ) = \frac { 3 } { 8 } x ^ { 2 } , 0 \leq x \leq 2$ .

A) $\frac { 5 } { 2 }$
B) $\frac { 5 } { 8 }$
C) $\frac { 3 } { 2 }$
D) $\frac { 3 } { 8 }$
E) none of these