Calculating percentages
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EXAMPLE: A student at the end of a class has earned 368 points on three 100 point tests and homework worth 100 points. What is the student's percentage of the toal possible points? percent = 100 x [ part / total] percent score = 100 x [ 368 points / 400 points possible] percentage = 92 % Here the total is 400 with 300 from tests plus 100 from homework. The earned points are 368. |
EXAMPLE: According to the 2010 CIA Factbook the world population is 6,924,690,017 or roughly 7 billion people. The CIA estimate of the population of China is 1,330,141,295. What percentage of the world's population is Chinese? Chinese percent = 100 x [ part / total] Chinese percent = 100 x [ 1,330,141,295 Chinese people/ 6,924,690,017 all people] percentage = 19 %
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EXAMPLE: The population of the United States is roughly 313,232,044. According to the 2011 CIA Factbook the world population is 6,928,198,253 (July 2011 est.). What percentage of the world population is American? % American = 100 x [ part / total] % American = 100 x [ 313,232,044 Americans / 6,928,198,253 all people] percentage = 5 %
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EXAMPLE: The number of income tax returns filed with the IRS in 2008 is reported to be 139,960,580. The population of the US is roughly 310,000,000 . What percentage of the US population filed a tax return with the IRS? % = 100 x [ part / total] % tax filers = 100 x [ 139,960,580 tax filers / 310,000,000 Americans ] percentage = 45 %
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EXAMPLE: A shopper has negotiated a car loan with an interest rate of 1.9% per year. The loan period is 5 years. What is the cost of the car loan if the car price is $21,000? Cost = loan amount x interest rate/ year x number of years Cost = $21,000 x 1.9 % / year x 5 years Cost = $21,000 x [ 1.9 /100] x 5 Cost = $21,000 x [ 0.019 ] x 5 Cost = $1995 . The total price will be $21000 + $1995 = $22995 To access a loan and/or interest calculator visit these pages.
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EXAMPLE: The yearly increase in the Chinese population is 0.49 % according to the 2010 CIA Factbook. The CIA estimate of the population of China is 1,330,141,295. How many Chinese are born each year? Remember the % term means per 100. increase in number of Chinese / year = [ yearly increase rate] x [ total] increase number Chinese / year = [0.49 % / year] x [ 1,330,141,295 persons] 0.49% / year = 0.49 per 100 / year ; since the term % = per 100 increase number Chinese / year = [ 0.49 person / 100 per year] x [ 1,330,141,295 persons] number Chinese / year = [ 0.0049 person/ year ] x [ 1,330,141,295 persons] = 100 x [ 1,330,141,295 Chinese people/ all people] increase in number of Chinese = 6,517,692 Chinese people / year |
