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Veronica is planning to make muffins from a mix. The package says each muffin will be 230 calories and 60 calories will be from fat. What percent of the total calories is from fat? (Round to the nearest whole percent.)

26%

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The brownie mix Ricardo plans to use says that each brownie will be 190 calories, and 70 calories are from fat. What percent of the total calories are from fat?

37%

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Find percent increase and percent decrease

People in the media often talk about how much an amount has increased or decreased over a certain period of time. They usually express this increase or decrease as a percent    .

To find the percent increase    , first we find the amount of increase, which is the difference between the new amount and the original amount. Then we find what percent the amount of increase is of the original amount.

Find percent increase.

Step 1. Find the amount of increase.

  • increase = new amount original amount

Step 2. Find the percent increase as a percent of the original amount.

In 2011 , the California governor proposed raising community college fees from $26 per unit to $36 per unit. Find the percent increase. (Round to the nearest tenth of a percent.)

Solution

What are you asked to find? the percent increase
Choose a variable to represent it. Let p = percent.
Find the amount of increase. .
Find the percent increase. The increase is what percent of the original amount?
Translate to an equation. .
Divide both sides by 26. .
Round to the nearest thousandth. .
Convert to percent form. .
Write a complete sentence. The new fees represent a 38.4% increase over the old fees.
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In 2011 , the IRS increased the deductible mileage cost to 55.5 cents from 51 cents. Find the percent increase. (Round to the nearest tenth of a percent.)

8.8%

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In 1995 , the standard bus fare in Chicago was $1.50 . In 2008 , the standard bus fare was $2.25 . Find the percent increase. (Round to the nearest tenth of a percent.)

50%

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Finding the percent decrease    is very similar to finding the percent increase, but now the amount of decrease is the difference between the original amount and the final amount. Then we find what percent the amount of decrease is of the original amount.

Find percent decrease.

  1. Find the amount of decrease.
    • decrease = original amount new amount
  2. Find the percent decrease as a percent of the original amount.

The average price of a gallon of gas in one city in June 2014 was $3.71 . The average price in that city in July was $3.64 . Find the percent decrease.

Solution

What are you asked to find? the percent decrease
Choose a variable to represent it. Let p = percent.
Find the amount of decrease. .
Find the percent of decrease. The decrease is what percent of the original amount?
Translate to an equation. .
Divide both sides by 3.71. .
Round to the nearest thousandth. .
Convert to percent form. .
Write a complete sentence. The price of gas decreased 1.9%.
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The population of one city was about 672,000 in 2010 . The population of the city is projected to be about 630,000 in 2020 . Find the percent decrease. (Round to the nearest tenth of a percent.)

6.3%

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Last year Sheila's salary was $42,000 . Because of furlough days, this year her salary was $37,800 . Find the percent decrease. (Round to the nearest tenth of a percent.)

10%

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Practice Key Terms 2

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Source:  OpenStax, Prealgebra. OpenStax CNX. Jul 15, 2016 Download for free at http://legacy.cnx.org/content/col11756/1.9
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