Question

At the local dairy farm, Kareem buys a 32-oz container of yogurt for $2.56. Jonah buys a 6-oz container of yogurt for $0.48. Are the cost, y, in dollars and the amount of yogurt, x, proportional? Explain. Write an equation to represent this relationship.

Answer 1

The ratios 2.56/32 and 0.48/6 are equivalent; y = 0.08x.

Explanation:

$2.56 for 32 oz is a unit price of $2.56/(32 oz) = $0.08/oz

$0.48 for 6 oz is a unit price of $0.48/(6 oz) = $0.08/oz

The unit prices are equal, so the cost of both sizes are proportional.

If x is the weight in oz, multiply the weight by 0.08 to get the cost, y, in dollars.

y = 0.08x

The ratios 2.56/32 and 0.48/6 are equivalent; y = 0.08x.