A company that produces calculators estimated that the profit \(P\) (in dollars)
from selling a particular model of calculator was
$$P=-152 x^{3}+7545 x^{2}-169,625, \quad 0 \leq x \leq 45$$
where \(x\) was the advertising expense (in tens of thousands of dollars). For
this model of calculator, the advertising expense was \(\$ 400,000(x=40)\) and
the profit was \(\$ 2,174,375.\)
(a) Use a graphing utility to graph the profit function.
(b) Use the graph from part (a) to estimate another amount the company could
have spent on advertising that would have produced the same profit.
(c) Use synthetic division to confirm the result of part (b) algebraically.