Question

Laura spent $20 for 5 books. Bryan spent $36 for 9 books. If this is a proportional relationship, what is the constant of proportionality between money and books bought?

Answer 1

The answer is that each book is 4$. We know this because 5 times 4 is 20 which is true for the problem and 9 times 4 is 36 which is true for the problem

Answer 2

4 dollars per book

Explanation:

For ever book, 4 dollars is added to the total amount