Suppose that a certain state has 794,000 people. Let the gross income for the i^th person be denoted by G_i , the taxes for the i^th person be denoted T_i , and the disposable income for the i^th person be denoted D_i . Suppose that the mean gross income per year is $50,000, and the average taxes per year is $7500.

a.) If the individual disposable income is the gross income minus taxes, write down the equation for D_i

b.) Find the average disposable income per year for the entire state.

c.) Find the total taxes per year for the entire state, and the total gross income for year for the entire state.

d.) Find the total disposable income per year for the entire state.