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## Statistics and probability

### Course: Statistics and probability > Unit 1

Lesson 1: Analyzing one categorical variable- Identifying individuals, variables and categorical variables in a data set
- Individuals, variables, and categorical & quantitative data
- Reading pictographs
- Read picture graphs (multi-step problems)
- Reading bar graphs
- Reading bar graphs: Harry Potter
- Creating a bar graph
- Create bar graphs
- Reading bar charts: comparing two sets of data
- Read bar graphs (2-step problems)
- Reading bar charts: putting it together with central tendency
- Reading pie graphs (circle graphs)
- Picture graphs (pictographs) review
- Bar graphs review

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# Reading bar graphs: Harry Potter

Sal interprets a bar graph. Created by Sal Khan.

## Want to join the conversation?

- Aren't points usually given in 5s, 10s, 20, and 50s?(29 votes)
- Usually yes, but there's always an exception to everything.(8 votes)

- When Sal said "Huffenpuff", I felt that.(23 votes)
- Dumbledore: 1000 points to Gryffindor because Harry sneezed(13 votes)
- No, it's 1000 points to Gryffindor because Harry exists, 10000 points from Slytherin because Tom Riddle tried to kill Harry.(5 votes)

- why is this a statistical question ?(6 votes)
- If you take anything, and compare it against something else......you can make a comparison. If you can compare something, you can perform statistical analysis.(8 votes)

- the point was too low, with Hermione on Gryffindor, and Harry won 50 points to be the "chosen one"(Malfoy speech) 'dunbome-dore' favorite student. Gryffindor will get 80 point every day! And that "Slytherin"(James speech) will get 30 point down.----> snape + the carrow + That Umbridge women VS professor lockhart + professor Moody (that barty crouch) + Dumbodole + slughorn = 30 point from Slytherin every day.(4 votes)
- The first class of the day must have been potions class with Professor Snape.(4 votes)
- This is interesting(3 votes)
- What if the bar graph for Slytherin, for example, is in between two numbers (eg. in between 4 and 5) but is closer to 5 than 4. So do we round up the value and assume 4.5?(1 vote)
- i would think it would be considered 5 not 4.5(2 votes)

- what is the difference between a histogram and a bar graph(2 votes)
- Here's a website that should help you understand: http://shodor.org/interactivate/discussions/HistogramsVsBarGraph/(3 votes)

- is a histogram and bar chart the same thing(2 votes)
- Great question. No, because a bar is used to display a categorical data. Histograms are used to present continues data. That's the difference.(3 votes)

## Video transcript

At Hogwarts, there are
four houses-- Gryffindor, Hufflepuff, Ravenclaw,
and Slytherin. The bar chart below shows
the number of house points that each house received today. How many house points
did Hufflepuff receive? So if we look at
this bar chart, we could assume that this column
right over here is Hufflepuff, because it's the
only one that starts with an H. This will be
Gryffindor, this is Ravenclaw, and this must be Slytherin. And so, if we look
at Hufflepuff's bar, it looks like they have
3 points scored today. So let's put 3 points. All right, let's try one more. So here they're saying,
how many house points did Slytherin receive? So this is going
to be Slytherin, and it looks like they
received 4 points.