In the 1990s, the number of target stores increased from 420 stores to 914 stores. what was the percent increased in the number of target stores in the 1990s?

Divide 914/420, move the decimal over to the right two places and you'll get approximately 217.5%

EDIT: My mistake, read question wrong.


117.62% 
Subtract the difference and divide by original number (: Move decimal place over two places.