Question

If p(t) is the profit (in dollars) that I expect my business to earn t years after opening, use functional notation to express my expected profit after 4 years and 6 months.

Answer 1

Is p(t) the total profit, annual profit or monthly profit?

If it is the total (cumulative) profit after 4 1/2 years, then the answer they are looking for is just
p(4.5)