Hi there! To solve for percent increase, we can write and solve a proportion. It would be set up as change/original = x/100, where change is the distance between the two numbers and the original number is the previous number. 1,200 - 900 is 300. 900 is the original number. The proportion would be set up like this:
300/900 = x/100
Let's cross multiply the values. 300 * 100 is 30,000. 900 * x is 900x. That makes 30,000 = 900x. Now, divide each side by 900 to isolate the x. 900x/900 cancels out. 300,000/900 is 33.33333 or 33% when rounded to the nearest whole number. There. x is approx. 33% increase.
