Question

A small grocery store offers two different brands of milk.

Brand A 2% milk costs $3.50 a gallon.
Brand B whole organic milk costs $3.00 for a half-gallon plus a one-time deposit of $1.50 for the glass jug. Once the glass jug deposit has been paid, the jug can be brought back to the store and the deposit doesn't have to be paid for each additional half-gallon milk that is purchased.
Graph the cost of milk for the brand that is proportional.

Answer 1

the total cost of milk for Brand B will pass through the points (0,1.50) and (0.5,4.50).

Explanation:

Brand A 2% milk costs $3.50 a gallon. If 0 gallons of milk are purchased, the cost is $0. If 1 gallon of milk is purchased, the cost is $3.50. So, the ray representing the total cost of milk for Brand A will pass through the points (0,0) and (1,3.50).

Brand B whole organic milk costs $3.00 for a half-gallon, plus a one-time deposit of $1.50 for the glass jug. At 0 gallons, the cost is $1.50 for the deposit. At 0.5 gallons, the cost is $3.00 + $1.50, or $4.50. So, the ray representing the total cost of milk for Brand B will pass through the points (0,1.50) and (0.5,4.50).

Since Brand A goes through the origin, Brand A is proportional. The correct graph is shown below.