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7th Grade Math / Lesson 5: Frequency Distributions

Frequency Distribution
What will we be learning in this lesson?


  • In this lesson you will learn how to make frequency distributions to display data.
Vocabulary words are found in this purple color throughout the lesson. Remember to put these in your notebook.


Frequency Distribution


  • A frequency distribution is sometimes called a frequency table.

  • A frequency distribution keeps track of how many times a certain data value or group of data values appears.

  • Below is the list of ages of 20 people surveyed at the mall. We will use this list to create a frequency distribution of their ages.

    13, 48, 67, 16, 26, 28, 64, 33, 26, 47,
    25, 36, 57, 45, 43, 18, 17, 38, 26, 16


Frequency Distribution


Ages


13, 48, 67, 16, 26, 28, 64, 33, 26, 47,
25, 36, 57, 45, 43, 18, 17, 38, 26, 16


There are too many numbers that only appear one time each. It will not be worth making a frequency distribution for each number separately. Let's group the numbers. Maybe have one group be under 15. Another group from 16 to 25. Another from 26 to 35, then 36 to 45, then 46 to 55, perhaps the last group be over 55.

15 and under

  16 to 25
  26 to 35
  36 to 45
  46 to 55
  over 55


Frequency Distribution


Ages


13, 48, 67, 16, 26, 28, 64, 33, 26, 47,
25, 36, 57, 45, 43, 18, 17, 38, 26, 16


Now you need to keep track of how many times a value occurs from each of the groups. Do this by making tally marks in the Tally column.


Frequency Distribution


Ages


13, 48, 67, 16, 26, 28, 64, 33, 26, 47,
25, 36, 57, 45, 43, 18, 17, 38, 26, 16


Now you need to add up the tally marks and write the number of times each group of numbers appeared from our list of ages.


  • Can you create a frequency distribution for a set of data?
  • Go back to the classroom to get to your homework and any other items you need to attend to.