How do you know whether two quantities x and y are proportional? A. Every ratio for related pairs of x and, is equivalent.
B. Every sum x + y is the same for related pairs of x and y.
C. Every x term is a multiple of the previous term.
D.
Every difference x - y is the same for related pairs of x and y.

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?