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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

Reading Bar Graphs. Created by Sal Khan and Monterey Institute for Technology and Education.

## Want to join the conversation?

- Is there any exercise for this?(71 votes)
- I'm struggling in reading bar charts 3 and I was wondering if someone could help me understand how to solve finding the range as well as the mid-range. Can someone please help?(16 votes)
- To find the range, subtract the smallest number from the largest number. To find the mid-range, add the smallest number and the biggest number together then divide by 2.(30 votes)

- You could estimate too right?(5 votes)
- estimating is when you find an answer close to the real one. so when you estimate the right answer, it would still be estimating.(4 votes)

- What is a midterm exam means(3 votes)
- They are exams that you take half way through the year/term, to measure how much you have grown...(6 votes)

- I wonder why coordinate graphs arnt 3D?(4 votes)
- They can be! Right now you're just working on how to use a 2D or two-dimensional graph with only two planes (x and y), but if you added a third plane (say "z") you could plot coordinates in 3D! In this situation, you would have three numbers for each point on the graph instead of two like this (0, 1, 6).(4 votes)

- UMMM how do u do this i need help!!(3 votes)
- So basically you’re trying to find out who improved the most...

So if someone’s middle term score is more than the final term score then they didnt improve ...they got worse.And this happend for Jeff and Marta... Somthe people who did improve are:

Jasmine

Nevin

Alejandra

But the question isnt who improved,Its who improved*the most*

So you have you have to find out *how much they improved *

Jasmine went from 73 to 78

Nevin went from 83 to 88

Alejandra went from 82 to 95

And if you want to find who improved most you have to see who had the biggest difference because the person who improved the most is not the person with the most .....

So these are the difference

Jasmine:5

Nevin:5

Alejandra:13

so therefore Alejandra is the the most improved

I really hope this helped

(it took me forever to write it)(4 votes)

- How do you find the mean?(3 votes)
- Add all the numbers and divide by how many numbers there is. For example, you are asked to find the mean of 1, 2, 3, 4 and 5. All you need to do is add 1 + 2 + 3 + 4 + 5 = 15. Now, to find the mean, divide the total by the number of terms. There are 5 so 15/5 = 3.(3 votes)

- Is this a exercise for our brain...😁😁(3 votes)
- Khan Academy is meant to exercise our brains! Keep going; you’ll get stronger!(2 votes)

- is sal assuming genders(3 votes)
- what is the use of bar graphs(2 votes)

## Video transcript

Based on the data below,
which student's score improved the most between the
midterm and final exams? And so they give us
this data in terms of a bar graph for each student. We actually have two bars
that show the midterm in blue and then the final exam in red. And they tell us that here--
midterm in blue and final exam. And sometimes this is called
a two-column bar graph because for each student here
you have two columns of data. So if you were to actually
look at the data itself, you have the midterm
data and then you have the final exam data. Now, they're asking us which
student's score improved the most between the
midterms and the final exams? So if we look at
Jasmine right over here, might as well start
with her since she's the most to the left. It looks like she definitely
did improve from the midterm to the final. It looks like in the
midterm, if I had to guess, this looks like about
a, I don't know, it looks like she got
maybe about a 72 or 73 on the midterm. I'm just guessing because I
don't know the exact number. And then it looks like on the
final she got, I don't know, that looks like maybe a
77 or 78 approximately. So she improved a little
bit, about five points from the midterm to the final. The way that they've
given us this information, we don't know the exact
numbers because it's not super precise in terms
of marking off the bars, but hopefully it'll
become obvious when we look through
everyone's scores. Let's look at Jeff. So Jeff actually did worse from
the midterm to the final exam. He got looks like over
an 85 on the midterm and then on the final he
got about 84 or an 85. So he actually went down. So it's definitely not Jeff. He definitely did
not improve the most. He actually went down. Next, if you think
about Nevin, it looks like Nevin actually
improved about the same amount as Jasmine. On both scores, I don't know if
Nevin is a boy or girl's name, this person on both tests, this
person did better than Jasmine, but it looks like the actual
improvement is about the same. Looks like they went from
about 83 to, I don't know, about an 88. I'm just estimating
it, just trying to look at this axis
right over there and estimating what
those scores are. So Nevin and Jasmine right now,
based on the three we've seen, are tied for the lead. Now let's look at Alejandra. Now Alejandra-- OK,
so this jumps out. She definitely improved
dramatically from the midterm to the final exam. It looks like on the midterm
she maybe got an 81 or an 82. So maybe this was an 82
she got on the midterm, and then on the final, it
looks she got about a 95 on the final. So there's dramatic improvement. So right now Alejandra
is the leading contender for most improved from
the midterm to the final. And then finally
Marta, right over here, it looks like she actually
got worse from the midterm to the final. She scored in the mid-90s
in the midterm and then low 90s in the final. So she's definitely
not the most improved. So the winner here is Alejandra. Alejandra is the most
improved between the midterm and the final exam.