27. you purchase 9.25 gallons of gasoline at $3.15/gallon. you also buy gum ($1.10) and windshield wiper fluid ($4.97). the state has a food tax of 4% and you give the clerk $30.00 cash. you pay the rest with your debit card. how much is charged to your debit card?
a) $35.21
b) $5.21
c) $35.25
d) $5.25

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?