GMAT Verbal Reasoning Practice Test 3

In Millington, a city of 50,000 people, Mercedes Pedrosa, a realtor, calculated that a family with Millington’s median family income, $\mathrm{\$}28,000$ a year, could afford to buy Millington’s median-priced $\mathrm{\$}77,000$ house. This calculation was based on an 11.2 percent mortgage interest rate and on the realtor’s assumption that a family could only afford to pay up to 25 percent of its income for housing.
Which of the following corrections of a figure appearing in the passage above, if it were the only correction that needed to be made, would yield a new calculation showing that even incomes below the median family income would enable families in Millington to afford Millington’s median-priced house?