Mean, Median and Mode

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Mean, Median and Mode

• A 6th Grade Math Presentation

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What are mean, median and mode
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Mean

• The mean is the average of a group of numbers.
  We get an average by adding the group of numbers
  together and dividing the total by their number.
• Example
• 1 4 9 11 5 30 and 30/56
• The mean for this set of numbers is 6.

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When would we use Mean

• Suppose you want to know what your numerical
  average is in Ms. Rufinos math class. Let's say
  your grades so far are 80, 90, 92, and 78 on the
  four quizzes you have had.
• To find your quiz average, add up the four
  grades 80 90 92 78 340
• Then divide that answer by the number of grades
  that you started with, four 340 / 4 85.
• So, your quiz average, or mean, is 85!

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Now You Try!
Find the mean for the test scores.
Answer 96 87 92 78 100 453 453/5
90.6
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Median

• The median is the middle number in a set of
  numbers when placed in numerical order.
• Example
• 1, 4, 5, 9, 11
• In the above number set, the middle number, or
  median, is 5.

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When would we use Median

• Suppose you are an adult looking for a job. You
  interview with a company that has ten employees,
  and the interviewer tells you that the average
  salary is 200 per day. Wow, that's a lot of
  money! But that's not what you would be making.
  For this particular company, you would make half
  of that. Each employee makes 100 per day, except
  for the owner, who makes 1100 per day.
• How do they get 200 for average then?! Well,
  let's take a look Nine employees make 100, so
  adding those up is 9 x 100 900. Then the owner
  makes 1100, so the total is 1100 900
  2000.
• Divide by the total number of employees, 10, and
  we have 2000/10 200.
• Because the owner makes so much more than
  everyone else, her salary "pulls" the average up.
  A better question to ask is, "What is the median
  salary?
• To find the median salary, we look at the
  salaries in order 100, 100, 100, 100, 100, 100,
  100, 100, 100, 1100. This is an even number of
  salaries, so we look at the middle two. They are
  both 100, so the median is 100.

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BUT WAIT! THERES A CATCH!

• What if there is an even amount of numbers in the
  set and there is no obvious median?!
• Look at the quiz grade example again 90, 80, 92,
  78. First list the numbers in order 78, 80, 90,
  92. The two middle ones are 80 and 90. So do we
  have two medians? No, we find the mean of those
  two 80 90 170, and 170 / 2 85.
• So 85 is the median!

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Now You Try!
Find the median of Lizs test grades.
Answer 78, 92, 87, 92 First, put the numbers in
numerical order. 78, 87, 92, 92 87 92 179
179/2 89.5
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Mode

• The mode is the number that occurs most often in
  a set of numbers.
• Example
• 2, 4, 5, 7, 7
• The number that occurs most often, or the mode,
  in the above set of numbers is 7.

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When would we use Mode

• Suppose you interview with a company that has 10
  general employees, 7 assistants, 3 managers, and
  1 owner. For this company, the mean salary is
  400, and the median is also 400. But you are
  applying for the position of general employee,
  whose starting salary is 100!
• Why are the mean and median so far away? Well,
  the 10 general employees each make 100. The 7
  assistants each make 400, the 3 managers each
  make 900, and the owner makes 1900. If you do
  the math to find the median or mean, 400 is the
  answer (try it!).
• So what can you do? The mode is the type of
  average you want to know in this situation. The
  mode is 100 because that number occurs ten
  times, which is more than any other number
  occurs.

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Now You Try!
Find the mode of the test scores the students
received.
Answer The mode is 98 because it is the most
frequent test score.
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Gummy Bear Activity

• Using the bag of gummy bears that have been
  handed out to you, as a class we will complete
  the following activities to find mean, median and
  mode together!

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How many gummy bears
2

• of red gummy bears?

of green gummy bears?
4
of yellow gummy bears?
5
of orange gummy bears?
7
of white gummy bears?
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Find the Mean

• 2 red, 4 green, 5 yellow, 7 orange, 7 white
• 2 4 5 7 7 25 gummy bears
• 25/5 5
• The mean of the gummy bears is 5.

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Find the Median

• 2 red, 4 green, 5 yellow, 7 orange, 7 white
• 2, 4, 5, 7, 7
• The median is 5.

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Find the Mode

• 2 red, 4 green, 5 yellow, 7 orange, 7 white
• 2, 4, 5, 7, 7
• The mode is 7.

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Lets Do a Quick Recap!

• http//www.youtube.com/watch?vuydzT_WiRz4

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Great Job Today Ladies and Gentlemen!!Thanks for
being super students!
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This presentation was made with by Ms. Rufino