Percent Error

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Percent Error

• Alex Rhoads
• Jim Jurgielewicz

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What is Percent Error?

• Percent Error measures the accuracy of an
  experiment.
• Percent Error was devised to find how close your
  experiment came to equaling the accepted value.

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Accepted Values

• In every percent error problem, you are given an
  accepted value, also known as actual values, for
  the experiment.
• This accepted value becomes the denominator in
  your Percent Error equation.

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Accepted Values Contd

• For instance The accepted value for 1 foot is 12
  inches, but when you measure it you find it to be
  only 11.5 inches.

• The 12 inches is the accepted value and you must
  find the percentage of error in your findings.

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Example

• The length between bases on a baseball field is
  known to be 90 ft. When measured by a group of
  students, they found the length to be 87 ft. What
  is the accepted value?

• A.) 87 ft.
• B.) 3 ft.
• C.) 90 ft.
• D.) -3 ft.

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Incorrect

• Sorry, you got the wrong answer.
• Click on the following link to review accepted
  values.
• Accepted Value

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Congratulations!

• Youre Correct
• Advance to the next slide to learn about using
  the Percent Error Formula

    
 

       

 
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Formula for Percent Error

• The Formula for Percent Error is

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Formula Contd

• This formula can be used for all kinds of
  experiments in order to see how quantitative your
  experiment was conducted
• Back to Example 1
• Back to Example 2
• Back to Example 3

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Example 1

• After finishing an experiment, John finds that
  the mass of a brick he weighed was 33.4 grams.
  Mr. Wolfe says that his accepted value for the
  mass was 32.7 grams. What was Johns percent
  error?

• A.) 66.1
• B.) 2.14
• C.) 0.7
• D.) .0214

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Incorrect

• Sorry, you got the wrong answer.
• Click on the following link to review the percent
  error formula.
• Percent Error Formula

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Good Job!

• Nice work, you got it right
• Continue on to the next example.
• Example 2

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Example 2

• Mr. Wolfe tells you that the accepted value of
  NaCl produced in a reaction is 23.7 grams. You
  find that there are 29.2 grams produced in your
  experiment. What is your percent error?

• A.) 23.2
• B.) 81.4
• C.) .188
• D.) 18.8

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Incorrect

• Sorry, you found the wrong answer.
• Click on the following link to review how to find
  percent error.
• Review Percent Error

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Nice Job

• Congratulations, you got it right!
• Go on to the third and final example
• Example 3

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Example 3

• A.) .0265
• B.) 26.5
• C.) 265
• D.) 7

• While conducting an experiment in Mr. Weiss
  class, he tells you that acceleration due to
  gravity is 9.8 m/s2. After your experimentation,
  you find it to be 12.4 m/s2. What is your Percent
  Error?

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Incorrect ?

• Sorry, you got the wrong answer.
• Please return to Example 3 to try again.
• Example 3

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Correctamundo

• Congratulations, you got the right answer.
• Youve successfully mastered the art of Percent
  Error.
• Proceed to the next slide to review what youve
  learned.
• Review

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Percent Error Review

• Percent Error finds the amount that a conducted
  experiment strayed from the accepted value.
• The formula for this is