Use proportional relationships to solve the following problem. Riley needs to earn enough money to purchase a new jacket. The one he likes the best is 49.99. His state sales tax is 7.25. How much money does he need to earn? Round to the nearest dollar.

1 answer

To find out how much money Riley needs to earn, we can set up a proportional relationship equation.

Let x represent the amount of money he needs to earn.

The amount of money he needs to earn is directly proportional to the price of the jacket.

The proportion is: x/49.99 = 1/1

Cross multiplying gives: x = 49.99

Since the state sales tax is 7.25%, we need to add it to the cost of the jacket.
The amount of money he needs to earn is directly proportional to the state sales tax.

The proportion is: 7.25/100 = (49.99 + x)/49.99

Cross multiplying gives: 724.75 = 4999 + x

Subtracting 4999 from both sides gives: x = 724.75 - 4999

Simplifying gives: x = -4274.25

Since we cannot have negative money, Riley needs to earn $4,275 to purchase the jacket.