Answer:
$180
Step-by-step explanation:
If Fiona earned 15% commision on what <em>she</em> sold, that means that we have to make a proportion to see how much she made.
15/100=x/1200
This is because 15/100 is the same as 15%. An easier way of doing this is just multiplying 0.15x1200 because that's basically how much she earned.
But, if we solve the proportion 15/100=x/1200, we get:
100x=18,000
Now, we divide each side by 100 to find <em>x</em>. Thus,
100x/100=18,000/100.
And,
x=180.