Given P=f(x)\displaystyle {P}={f{{\left({x}\right)}}} where P\displaystyle {P} is the profit in thousand of dollars and x\displaystyle {x} is the number of units sold (measured in hundreds), which of the following is the best interpretation of f1(\displaystyle {{f}^{{-{{1}}}}{(}}6)=\displaystyle {)}= 9.5?