Question

3:4 = 15:20 True or False. Explain your reasoning.

Answer 1

3:4 = 15:20 because 3 can go into 15 an 4 can go into 20.

Answer 2

the question is if the two proportions are equal:
3:4
= 3(5):4(5)
that is, we just multiply both sides of the proportion by the same number and so we have:
3:4
= 3(5):4(5)
= 15:20
therefore:
3:4 = 15:20