Which proportional relationship has the greatest rate of change?

Alength on a map is 7.5 inches. thescale is 1 inch: 5 miles. what is theactual distance? a 1.5 miles c 12.5 milesb 2.5 miles d 37.5 miles

Four individuals pool money together to start a new business and agree to split the profits equally. n invests $6,000, x invests $2,000, y invests $8,000 and z invests $4,000. if the profits for the first month were $100,000, y receives than if the profits were divided in proportion to how much they invested.

How can you tell when x and y are not directly proportional?