National income (ni) is the sum of the incomes that all individuals in an economy earn in the forms of wages, interest, rents, and profits. it excludes government transfer payments and is calculated before any deductions are taken for income taxes. during the period 1994-2004, the ni of australia grew about 5.2% per year, measured in 2003 u. s. dollars. in 1994, the ni was $4 billion. assuming this rate of growth continues, in what year will the ni reach $15 trillion?

Data from 2005 for various age groups show that for each $100 increase in the median weekly income for whites, the median weekly income of blacks increases by $105. also, for workers of ages 25 to 54 the median weekly income for whites was $676 and for blacks was $527. (a) let w represent the median weekly income for whites and b the median weekly income for blacks, and write the equation of the line that gives b as a linear function of w. b = (b) when the median weekly income for whites is $760, what does the equation in (a) predict for the median weekly income for blacks?