Suppose That the Marginal Revenue for a Retailer Is 6 $x ^ { 2 }$

Multiple Choice

Suppose that the marginal revenue for a retailer is 6 $x ^ { 2 }$ - $\sqrt { x }$ + x dollars at sales level x. If 4 units are currently being sold, what is the extra revenue received from the sale of 5 additional units?

A) $152
B) 1304 + $\frac { 259 } { 6 }$ ≈ $1347.17
C) 568 + $\frac { 42 } { 17 }$ ≈ $570.47
D) $\frac { 11 } { 6 }$ ≈ $1.83
E) none of these