The population of Grand Island Nebraska grew by 600000 people between 1995 and 2005 one fifth more than the town council predicted The town council originally predicted what?

They originally predicted 500,000. Twenty percent more than 500,000 is 600,000.

So the factor of difference here is 1.2. Dividing 600,000 by 1.2 gives 500,000.

You cannot take 20% of the final number when the question says 20% more than the original prediction. You must divide the final population by the whole number (ie., 1) and the percentage, not multiply then subtract from the final.

So the correct formula is:

1.2x = 600,000.

x = 600,000 / 1.2

x = 500,000