Discrete and continuous random variables | Probability and Statistics | Khan Academy

Defining discrete and continuous random variables. Working through examples of both discrete and continuous random variables.

Missed the previous lesson?

Probability and statistics on Khan Academy: We dare you to go through a day in which you never consider or use probability. Did you check the weather forecast? Busted! Did you decide to go through the drive through lane vs walk in? Busted again! We are constantly creating hypotheses, making predictions, testing, and analyzing. Our lives are full of probabilities! Statistics is related to probability because much of the data we use when determining probable outcomes comes from our understanding of statistics. In these tutorials, we will cover a range of topics, some which include: independent events, dependent probability, combinatorics, hypothesis testing, descriptive statistics, random variables, probability distributions, regression, and inferential statistics. So buckle up and hop on for a wild ride. We bet you're going to be challenged AND love it!

About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.

For free. For everyone. Forever. #YouCanLearnAnything

Subscribe to KhanAcademy’s Probability and Statistics channel:

[Zhim]

For those who don't quite understand, discrete R.V is for counting; continous R.V is for measuring.

[judsonl]

I'm going to COVID's version of a university right now - these Kahn Academy videos are way more helpful than my stats professor.

[mainguy]

I asked Chat GPT to explain like im 5 years old

"Alright, imagine you have some marbles. Discrete variables are like counting how many marbles you have. You can have 1 marble, 2 marbles, 3 marbles, and so on. Each number is separate and you can't have half a marble or a quarter of a marble.

Now, think about a jar of water. Continuous variables are like measuring how much water is in the jar. You can have a little bit of water, a medium amount, or a lot, and you can also have in-between amounts like half-full or one-third full. There's no limit to how much water you can have, and it can be any amount, not just whole numbers.

So, discrete variables are like counting marbles, where you can only have whole numbers, and continuous variables are like measuring water, where you can have any amount, even parts of it."

[DerrickTay]

I dont usually comment on such videos. But this is way too easy to understand from his explanation. I would have A's any class if all my lecturer are like him. Thumbs Up !!!

[pearcei]

we spent a whole day on just the definition of discrete vs continuous variables in class and i still didn't know it and then i learned it in less than 3 minutes here

[killerqueen]

I like the small snippets of commentary that are added into the lesson, like ants learning interstellar travel and how Usain Bolt is aging. It makes the video so much more fun to watch lol.

[cashele]

"the New Orleans zoo where I grew up" lmaooo

[pervertbismarck]

I learnt more in 11 minutes than 1 months. We need more teachers like him.

[khushigupta]

Khan Academy, you guys are doing a wonderful job. I was feeling dumb in class when it came to this topic but now I understood everything. Sad to see how the classroom learning doesn't help most of us.

[khanacademy]

Good question. It is not a question of the size of the population you are sampling from. It is a question of the possible values that each sample can take on. Mass can take on any value (including an irrational number if we don't get caught up with quantum mechanics) so it is a continuous random variable.

[AIONBERSERKER]

My professor made this whole thing seem so complicated. You explained it in less that 15 minutes :D

[thinkfeelsolve]

Thank you, sir.
Discrete random variables cannot be broken down into decimals or fractions.
There is no half an ant or half a person. but there can be half a second and one-fourth of a meter.
Discrete things are counted.
continuous things are measured.

[jonathanlind]

Very good explaining, I've had a hard time distinguishing the difference between disc. and cont. variables and you managed to tackle the very questions I had. Thank you!

[s_kaukab]

That was one good explanation, I've always stumbled upon how the heights or weights in a class are not discrete random variables, thanks Sal!

[tarunt]

Just looked it up, the teacher was pretty much on point, elephants range from about 2, 000-7, 000 kg.
(4, 000-14, 00 pounds)

[amalnazir]

Why is no one talking about when he said “maybe some ants have figured out some interstellar travel” 😂 7:58

[mithurajdas]

a good example of continuous random variable:Reading the temperature of a room throughout the day, its continuous since the temperature does not jump from 20 degrees to 22 degrees.so its continuous process.

[Chloe-jzpr]

Thanks for this video!! I was learning these definitions through online school due to quarantine and I just couldn't understand it. But this video helped me to finally get it. (:

[sina]

that moment when u realize the video is mentioning 2016 as a future year

[skatershawn]

Love how he called out Bolt would win in the 2016 Olympics!