Date: Tue, 16 Mar 1999 08:38:07 -0600 (CST) Subject: Percentages Name: Beth Question: If I have two figures and want to know the difference between them, in Percentage, how do I proceed with a calculation? Example: 67,800 - 56,000 = 11,800 What percentage does this difference represent? It's been about 0 years since High School, so I don't remember how to do this. Thank-you! Hi Beth You are asking a very important question. Whenever we talk about percent we have to ask "of what?".Consider this example. A \$100 item is increased in price by 10% and then the new price is decreased by 10%. Are you back to where you started? Let's try it. 10% means 0.10 so 10% of \$100 is 0.1x100 = 10 and so the new price is \$110 (10 + 10). Now we want to calculate the decrease in price.  But the decrease is 10% of \$110 and so the decrease is 0.10x110 = 11 and so the new price is \$99 (110 - 11). Surprise!     Now to return to your problem. The answer depends on whether you want to determine the difference as a percent of 56 000 or as a percent of 67 800. If you want the difference as a percent of 56 000 then you write the fraction 11 800/56 000.  If you want the difference as a percent of 67 800 then you write the fraction  11 800/67 800. In the 1st case the decimal is 0.2107.... To change this to a percent we multiply by 100 and so the difference as a percent of 56 000 is about 21.1%. In the 2nd case the decimal is 0.1740... and so the difference as a percent of 67 800 is about 17.4%. I hope that this helps. Jack Go to Math Central To return to the previous page use your browser's back button.