To determine the new amount you need to find out what 2/3 of 4 1/2 is equal to. What you see "of" in an algebraic expression or equation, replace it with (×).
We will use the equation 74.06-56.48=? To find the change in prices, aka how much more money was spent. That equals 17.58. So A, Michael spent $17.58 more than Denise.