Finding Percentage of Increase
Date: 06/07/2003 at 23:03:06 From: Chief Subject: Percentage increase Find the percentage increase: old, $50.50; new $75.75.
Date: 06/08/2003 at 01:28:55 From: Doctor Mike Subject: Re: Percentage increase Hello, You first figure out the amount of increase. That is 75.75 minus 50.50, which is 25.25. When you deal with percentages, you compare the increase with the original, which in your case is 50.50. (original = old) For me, it has always been easier to understand this comparison step by putting it in terms of a fraction before doing the percentage version of the answer. The fraction is increase ---------- before For this problem, the numbers for it are 25.25 ------- 50.50 This turns out to be exactly 0.5 or 1/2. Finally, the percentage is the fraction multiplied by 100. 100 times 0.5 is 50, so the answer is 50 percent. Put into words, it is a 50 percent increase to go from 50.50 to 75.75. Here is a similar problem where the numbers involved are easier. You should do the work to convince yourself that it is also a 50% increase to go from 50 to 75. You are adding 25 (half of 50 = 50 percent of 50) to get from 50 to 75. See? Good! Here is another useful related example. If you go from 50 to 100 you double the amount. That is, you add 100% of the original to get the new. This is a 100% increase. - Doctor Mike, The Math Forum http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.