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Bar graphs review

Bar graphs are a nice way to visualize categorical data. This article reviews how to create and read bar graphs.
A bar graph is a nice way to display categorical data.
For example, imagine a P.E. teacher has 4 soccer balls, 4 footballs, 7 tennis balls, and 8 volleyballs. We can display this data in a bar graph:
A bar graph shows the vertical axis labeled Number of balls. The horizontal axis is labeled, from left to right: Soccer, Football, Tennis, and Volleyball. The vertical axis is labeled from the bottom of the axis to the top of the axis as follows: 0, 2, 4, 6, and 8. The bar line for each type of book shows the following: Soccer bar line extends to 4, Football bar line extends to 4, Tennnis bar line extends to 7, and Volleyball bar line extends to 8.
Notice how the height of the bar above "soccer" is 4 units to show that there are 4 soccer balls. And the bar above "tennis" is 7 units high to show that there are 7 tennis balls. The "football" and "volleyball" bars work in the same way.
Want to learn more about bar graphs? Check out this video.

Practice set 1: making bar graphs

Problem 1.A
There are 4 purple, 5 yellow, 2 green, and 9 red lunch boxes.
Make a bar graph for this data.

Want to practice more problems like these? Check out this exercise.

Practice set 2: reading bar graph

Problem 2.A
The music store sells trumpets, flutes, and drums.
This bar graph shows how many of each instrument are at the store.
A bar graph shows the vertical axis labeled Number of instruments. The horizontal axis is labeled, from left to right: Trumpet, Flute, and Drum. The vertical axis is labeled from the bottom of the axis to the top of the axis as follows: 0, 2, 4, 6, 8, 10, 12, and 14. The bar line for each type of book shows the following: Trumpet bar line extends to 11, Flute bar line extends to 4, and Drum bar line extends to 14.
How many more trumpets are there than flutes?
  • Your answer should be
  • an integer, like 6
  • an exact decimal, like 0.75
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
more trumpets

Want to practice more problems like these? Check out this exercise and this more advanced exercise.

Want to join the conversation?

  • primosaur ultimate style avatar for user William Wise
    What is a parallel modified boxplot?
    (17 votes)
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  • blobby green style avatar for user BrightGlossy Brightly
    How to create Parallel modified boxplot
    (16 votes)
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  • duskpin seedling style avatar for user becca davis
    Why wasn't there a practice section for "Reading bar charts: Putting it together with central tendency?"
    (14 votes)
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  • blobby green style avatar for user adnanax
    in an example where the capacity of the car and number of seats given. shouldnt both be categorical instead of quantitative as there are fixed categories of cars based on number of seats either 2,4,5,6,7 and similarly the capacity is also categorized likewise.
    (3 votes)
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    • aqualine ultimate style avatar for user Rohan Suri
      No, they won't be called categorical because the difference between categorical and quantitave data boils to the simple rule whether we can perform valid arithmetic operations on it. For example the no of seats can be 2,4,5,6,7 (True) but you can perform arithmetic operations(addition on it) eg 2 seats + 2seats is 4 seats which makes perfect sense. So it is a quantitative variable in principle.
      However, suppose there is another variable called color of the car. Now color can be RED BLACK or Blue.
      In this case performing an arithmetic operation doesn't make sense :
      RED + BLACK doesn't make valid sense.
      So color of the car is a qualitative/categorical variable
      (9 votes)
  • starky seed style avatar for user Collins, Jacob
    does this txt thing work
    (4 votes)
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  • blobby green style avatar for user rava_ela
    if a mean test mark is 3 , what would be the value
    (4 votes)
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  • spunky sam red style avatar for user Youngblood,jack
    this is to easy
    (2 votes)
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  • winston default style avatar for user Victor Gutierrez
    What has been called here categorical data, has been called quantitative data in the first video of this unit. Just saying..
    (0 votes)
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  • blobby green style avatar for user 10055293
    What is a parallel modified boxplot?
    (1 vote)
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    • blobby green style avatar for user daniella
      In a parallel modified boxplot, each dataset is represented by its own box-and-whisker plot, and these plots are arranged in parallel or side by side for visual comparison. The box-and-whisker plot provides a visual summary of the distribution of a dataset, including key statistics such as the median, quartiles, and potential outliers.
      (1 vote)
  • blobby green style avatar for user suresh.b.yeruva
    curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?curiosity is the best who agrees with me?
    (1 vote)
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