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## Statistics and probability

### Course: Statistics and probability>Unit 2

Lesson 1: Displaying quantitative data with graphs

# Histograms

Here's how we make a histogram: 1. Collect your data and decide on the number and size of bins (categories) you want to divide your data into. 2. Count the number of data points that fall within each bin. 3. Draw a graph with the bins as the x-axis and the frequency counts as the y-axis. 4. Draw vertical bars to represent the frequency count for each bin. Created by Sal Khan and CK-12 Foundation.

## Want to join the conversation?

• Why do you call it a histogram? What does it mean, and what base word does it come from.
• in a histogram, when you skip a #, aren't you supposed to draw a break where the # skipped is? Why doesn't Sal do that
• He didn't actually skip the 5, he just put it there and didn't draw a bar, or u could think of it as drawing a bar with a height of 0.
• Does it have to be number frequency to differ from a bar graph? Wouldn't it be a histogram if you chart population? (# of Mexicans, #of African Americans, # of Asians, etc.)
• i don't think this is a clear representation of a histogram. this is more of a bar graph- a histogram is meant to have frequency density on the y axis (or so i've been taught). i want to know how to read a real histogram with frequency density on the y axis and measurement on the x axis can anyone point me in the right direction? thanks in advance
• histograms and bar graphs are not the same histograms are joined while bargraphs have spaces between the data
• The buckets are the groups of the different numbers: The 1 bucket, the 2 bucket, and so on
• How would you do this if you had all decimal numbers... For example, 1.2, 1.9, 5.6, 3.2, etc. I am confused, and my school work does not explain this very well.
• I am pretty sure that you work that out the same way, just with decimals
• I have to do a histogram for a group of data, and my survey question is "What is your favorite movie genre?" and my options were action, horror, adventure, fantasy, comedy, and romance. The results where:
action- 15
horror- 10
fantasy-5
comedy- 19
romance- 5
My problem is that I have no idea how to do a histogram that can portray this information.
• You would draw a histogram like in the video where the bottom would be the type of movie (action, horror, etc), and the left side would be numbers. Then draw bars to reflect the result for each type of movie.

Hope this helps.
• how do you create a frequency table and a histogram if you have 50 numbers? (Ex.1943,1950,1951)
• The same way it is done in the video starting at @.
Read your list of numbers one at a time and, for each number you read, add +1 to the corresponding counter. After having counted the number of occurrences of each number, you can divide by the total number of numbers to obtain their frequency.
• Hmmm Histogram looks a lot like a Bar graph