Sampling distribution example problem | Probability and Statistics | Khan Academy

Figuring out the probability of running out of water on a camping trip

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[ivinvirus]

My Stats lecturer always got me bored and couldn't understand a thing, I skipped 9 statistics lectures this semester, now that I'm looking at vids from khan academy, stats is pretty fun... its just the matter of teachers we get

[akshittuli]

This is so good....
I've probably learnt more statistics by watching these videos than I would have ever learnt by reading my textbook...
PS: for those who didn't get it, watch his previous videos

[mostinho]

Done thanks
Takeaway: when taking a sample from a normal distribution, the normal distribution of the sample has same meaning but different standard deviation related to the original distribution, based on the sample size. You can then calculate probabilities based on the sample’s normal distribution.
Var(S)=Var(X)/n where var(s) is new variance of the samples you took and var(x) is the variance of the distribution you are sampling from

[SkitzandGigglez]

You are a fantastic teacher sir. I've been learning about sampling distribution through an online certificate course, and while the instructor may go in depth with the formulas and theory, you have really made it click for me by showing HOW the sampling distribution can be APPLIED to making decisions. Thank you so so much!

[NoPretending]

This is gold! I have learned statistics all semester without going to professors lessons or even done anything else than doing old exams and practice problems. I have an exam two days from now and this helps me a lot, just to get my head around the actual concepts! I even didn't care to understand it very much, just did the math and got the answers right for the most part. But it's SO satisfying to understand the fundamentals, thanks yo you, SUPER TEACHER :D Greetings from Norway.

[jessylsm]

THANK YOU SOSOSOSOSO You are I signed in just to comment and like the video!

[Momo-qvby]

It really helps a lot these two graph helps me figure out the relationship between The population distribution and simple distributions!

[comfortolorunsaye]

Now my course material makes sense! Thank you!

[harsharangapatil]

In this entire unit this video was the one which helped me understand what is going on.

[fajardolanceo.]

i feel like he tried so hard to make it simple that it actually went complicated

[Badar]

Brilliantly broken down explanation; you absolute god

[Valemr]

I understood the problem completely thank you very muh.
As a side question: couldn't we solve the problem by just multiplying the mean and standard deviation by 50 so we would get a normal distribuiton of N(100, 35) and calculate P(X>110) ?

[davidtang]

The graphs he draws always mesmerize me.

[gl]

My stats professor always speaks so fast and doesn't explain much, I don't understand a thing. Your videos are so helpful and you teach a million times better.

[tarzan]

Very clear explanation. Thank you, very much.

[paragdighe]

I think this is a great video. At times slow on calculations..but that should be pardoned I guess :). The key is that "distribution of sample mean is always Gaussian" when the no of samples is 'good enough'. Here is a trick question I thought of: How does the probability get affected if reduce the number of men to 25 instead of 50 and reduce the water to 55 L from 110 ? :)

[norwayte]

Excellent. - And now... the probability that the world is facing a currency fight between nations...and the probability for US to get out save from this fight.

[shivan]

Ha haaa! I was struggling with this a few years ago. Now I rewatched the video and was able to do it by myself.

[jorgehevia]

Fantastic explanation...as the rest of all videos. Maybe some structure is needed to get a base from that knowledge improvement can be progressive.

[frankilalala]

honestly, it's most easy to learn statics of class, I love it. Thank you!!!!