I really need help with this word problem. I am totally stumped.I realize

So we start with the total amount and find out the proportion that each person invested -

Total amount - 9,000 + 7,000 + 4,000 = 20,000

Then we find out what proportion each one put in

9,000/20,000 = 45% or 0.45

7,000/20,000 = 35% or 0.35

4,000/20,000 = 20% or 0.20

It's a good idea to make sure your 3 figures add up to 100% or 1.00 before you go further!

Then, when you know that the third person put in 20% or 0.20 of the investment, then that person should also get 20% or 0.20 of the profit. So you multiply the profit by the decimal amount:

4,800 * 0.20 = $960

If you really wanted to be thorough, you could calculate everyone's share to make sure it adds up to the total profit.