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## Statistics and probability

### Course: Statistics and probability > Unit 2

Lesson 3: More on data displays# Reading line graphs

A line graph is way to visually represent data, especially data that changes over time. Let's take a look at an example. Created by Sal Khan.

## Want to join the conversation?

- What if the line went up and down but ended in the same place ?(6 votes)
- Then the trend wouldn't increase/decrease?(3 votes)

- So why do you look for the overall trend? Couldn't you look for the average?(2 votes)
- No, because the average does not help in finding trends.(10 votes)

- Why are more lines sometimes used if the number is increasing or decreasing?(5 votes)
- Would it be wrong if you explained some of it. Like if this question came up in an exam and you explained how sometimes it went up and sometimes it went down and then said that overall it went up. Would you loose any marks for the whole explanation and if you only explained it without the overall part then would it be correct?(4 votes)
- Uhh... No? Because if mostly the trend goes up than down then we can say that it is going up?(2 votes)

- this is a nice web site cool(2 votes)
- i'm having trouble with reading bar charts 3 what is midrange median range mode and mean(2 votes)
- I'm not sure what the midrange is BUT, the median is when you put the set of data into numerical order (10,15,18,19,20,20,26,27,30) then starting with the smallest cross out the number going back and forth between the biggest and smallest and cross them out untill you get to the middle. the middle number is your median, the median for this set of data is 20. the range is the maximum number (30) minus the minimum number(10) the range is 20 in this set of data. the mode for this set of data is the number that occurs most often therefor the mode is 20 ( i didn't know that the answers were mostly the same i just randomly came up with this set of data!) the mean is mean and hard, take all the numbers in the set of data and with a couculator add them all together then divide that num ber by the number of numbers in the set of data (9)he answer should be 20.555....

hope i helped!!:)(0 votes)

- Can a line graph possibly be more helpful than bar graph?(2 votes)
- Well... it depends on what you're comparing. Line graphs are useful for displaying smaller changes in a trend over time. Bar graphs are better for comparing larger changes or differences in data among groups.(0 votes)

- How do you find an equation from a line graph?(1 vote)
- This isn't a question I just wanted to say thanks to khan academy I have learned so much on this website 👍✌(1 vote)
- At probably1:19how is it falling then rising then falling then rising AGAIN but higher? Shouldn't it be more specific maybe?(1 vote)
- I think it is already specific enough and the fall and rise shows the stock price(1 vote)

## Video transcript

An investment firm
creates a graph showing the performance of a
specific stock over 12 months. Over the course of
the year, is the price of the stock rising,
falling, or staying the same? So over this axis right over
here, the horizontal axis, they have month by month. And we move forward in time--
July, August, September, October. And in this axis, the vertical
axis, we have the price. So, for example, in July
the price of this stock was a little over $10. Then in August, it moved up
to-- it looks like around $11. And then we could keep
going month by month. And this type of
graph right over here is called a line
graph because you have the data points
for each month. And then we connected
them with a line. And the reason why we
connect them with a line is to really see if there's
some kind of a trend here to really show that
you have something that's moving from one
price to another. And so line graphs
tend to be used when you have something
that's changing over time. Now, with that out of
the way, let's actually answer their question. Over the course of
the year, is the price of the stock rising,
falling, or staying the same? So on a month-to-month
basis, you have, for example, from July to August,
the price went up. Then from August to September,
the price went down. Then it went up for two months. Then it went down for a month. Then it went up for
a couple more months. Then it went really up
from February to March, went all the way
up to almost $17. Then it went down again. And then it kept going up again. But they're asking us not
did it go up every month. They're saying over
the course of the year is the price of the
stock rising, falling, or staying the same? And if you go from July, which
is where our data starts right over here, our price
was around $10. And even though there were a
few months where it went down, the overall trend is that
the price is going up. The overall trend is
that the price going up. And you can even see that. In July, it was $10. And then by June
of the next year, it was approaching--
I don't know, it looks like it's
about a little over $16, maybe almost $17. So it actually
had gone up a lot. They don't give us
July of the next year. But the overall
trend is definitely the upwards direction
right over here. And you can see it just visually
by looking at this line graph. Even though there's a
few bumps that go down, the overall direction is upward.