For the Probability Density Function $f ( t ) = \frac { 1 } { 2 } e ^ { - \frac { t } { 2 } }$

Multiple Choice

For the probability density function $f ( t ) = \frac { 1 } { 2 } e ^ { - \frac { t } { 2 } }$ on the interval $[ 0 , \infty )$ , find the probability that $t \geq 3$ . Round your answer to the nearest thousandth.

A) 0.112
B) 0.388
C) 0.183
D) 0.333
E) 0.223