Learn about Applications of Percent Change Now let’s look at using percent change for practical applications. The problem says that Sean bought an LCD monitor which is originally priced at $600.00 it was marked down by 45% so what did Sean paid for the monitor? So what do we know? We know that the original price = $600.00 we know that the percentage decrease in price is 45%. We need to find the final price of the monitor. Now, we know that the final price of the monitor equals the original price minus the reduction in price. The final price equals the original price minus the reduction in price. First let’s compute what is the reduction in price. So the reduction in price is what we are trying to find out. We know that the amount of decrease or the reduction in price is equal to 45% of original price. I’m going to create a little bit of extra space. So if the reduction in price is 45% of the original price which means it is 45% off $600.00. So if $600.00 was the original price and the reduction is 45%. So let’s write 45% as a fraction. So the reduction in price equals, instead of 45% let’s write it down as 45/100 multiplied by $600.00 which is equal to 45 x 600 is 27,000/100 which means if I divide both of these by their GCF which is 100 the reduction in price becomes $270.00 okay. So the price was reduced by $270.00 and we know that the final price equals original price minus reduction in price we can now compute the final price. So the final price equals the original price which was $600.00 minus the reduction in price which is $270.00 let’s take away 270 from 600 and left with $330.00 which is what Sean paid for the monitor.