The Average Number of Vehicles Waiting in Line at a Toll

Multiple Choice

The average number of vehicles waiting in line at a toll booth of a super highway is modeled by the function $\mathrm { n } ( \mathrm { x } ) = \frac { \mathrm { x } ^ { 2 } } { 0.5 ( 1 - \mathrm { x } ) }$ , where x is a quantity between 0 and 1 known as the traffic intensity. To the nearest tenth, find the average number of vehicles waiting if the traffic intensity is .81.

A) 1.6 vehicles
B) 3.5 vehicles
C) 6.9 vehicles
D) 8.5 vehicles