In 1965 the Economist F $n = - 3.93 + 132.61 s - 22.88 s ^ { 2 } + 1.311 s ^ { 3 }$

Multiple Choice

In 1965 the economist F.M. Scherer modeled the number, n, of patens produced by a firm as a function of the size, s, of the firm (measured in annual sales in millions of dollars) . He came up with the following equation based on a study of 448 large firms. Round your answer to two decimal places.
$n = - 3.93 + 132.61 s - 22.88 s ^ { 2 } + 1.311 s ^ { 3 }$
Find $\left. \frac { \mathrm { d } ^ { 2 } n } { \mathrm { ds } ^ { 2 } } \right| _ {= 4 }$ .

A) -12.3
B) -14.3
C) 31.46
D) -17.3
E) -9.3