Final answer:
To find the number that makes the ratio equivalent to 9:15, use the proportion 9/15 = x/45 and solve for x. The number is 27.
Step-by-step explanation:
To find the number that makes the ratio equivalent to 9:15, we can set up a proportion. The ratio 9:15 can be written as 9/15. Let x be the unknown number. We can set up the proportion as 9/15 = x/45. To solve for x, we can cross-multiply and solve the resulting equation.
Cross-multiplying gives us 9 * 45 = 15 * x. Simplifying further, 405 = 15x. Dividing both sides by 15, we find that x = 27. Therefore, the number that makes the ratio equivalent to 9:15 is 27.
Learn more about Finding a number in a proportion