please, please, work through the steps, i struggled to keep along as this was structured like it assumed we knew what was going on like that section with standard deviation I immediately got lost
Sal, great movie! Please make a (short) movie on William Gosset and his nick Student. When I was a student I thought that t-Student comes from a student untill I found the story on wikipedia. Sal - I took some courses on statistics, but no one ever derived the normal distribution or any other distribution. So my question is if you plan to make movies how to derive probability density functions like Gaussian, gamma, and so on? Sal, your Academy is the best academy on our planet!
So you say...(1.5-2.34)^2 + (2.9-2.34)^2+ (.9-2.34)^2+(3.9-2.34)^2+(3.2-2.34)^2+(2.1-2.34)^2+(1.9-2.34)^2 and divide all of that by n-1=6. This will give you the variance...and then just take the square root to get the standard deviation.
@6:32 you made it clear that it is the sampling distribution of sample means (and not simply the sample distribution), then how come is the sample mean at the centre? Isn't the population mean at the centre of sampling distribution of sample mean? Please Clarify, TIA
He uses the sample mean to estimate the population mean. That's the best we can do. Then, using that polulation mean, we compute the confidence interval where we have 95% possibility that the actual population mean is within that confidence interval around the estimated mean.
@@yuzhe6054 but the central value in a sampling distribution of means is always the population mean. I mean shouldn't the confidence interval be constructed around some other point on the graph, say to the right of the centre where our sample mean is located
@@shreyachawla988 Yea, there are chances that the sample mean is not close to the actual population mean. But that's the best we can get. If we want to skewed the centre of the sampling distribution, we won't know which way to skewed the mean, left or right, solely based on the sample we get. To play it safe, we just estimate the population mean with the sample mean and construct the confidence interval around that centre.
Interesting that this has a distinct name. We could just assume nothing about the initial distribution and proceed with the central limit theorem as usual :)
You can calculate the standard deviation of the samples by using the given numbers and mean. In other words, it is S. Why do we have to estimate the standard deviation of population as S, but then calculate the sample standard deviation as S/sqrt(n) ? why not the other way ?
I just want to say, "Whoever created statistics is pure evil!" I have to take headache medications after watching tutorials and trying to figure out the problems still long after the video has ended, sigh..
I need to know how you calculated standard deviation because I tried and did not get the same number. Need to quit assuming that people already know how to do part of the problem.
Old comment, but for those seeing it now, Khan Academy takes things step by step, and if they showed you how to do every calculation like standard deviation and mean in every video then the videos would be too long. They did previous videos on stdev and mean which you can go back and watch if you don't understand.
What's the probability that the instructor is going to ramble on, repeat himself multiple times as he writes, and regularly use the wrong words throughout the video?
good explanation, i still hate this though
please, please, work through the steps, i struggled to keep along as this was structured like it assumed we knew what was going on like that section with standard deviation I immediately got lost
You gotta watch the previous videos. If he explained every bit, each stats video would go on for 40 minutes.
"I did this ahead of time." But that is the information I need to know :(
Excellent explanation, thank you.
Sal, great movie! Please make a (short) movie on William Gosset and his nick Student. When I was a student I thought that t-Student comes from a student untill I found the story on wikipedia.
Sal - I took some courses on statistics, but no one ever derived the normal distribution or any other distribution. So my question is if you plan to make movies how to derive probability density functions like Gaussian, gamma, and so on?
Sal, your Academy is the best academy on our planet!
smicha7 .0
@TheBrotherStatic couldnt agree with you more.. final is next week! may god help us all!
So you say...(1.5-2.34)^2 + (2.9-2.34)^2+ (.9-2.34)^2+(3.9-2.34)^2+(3.2-2.34)^2+(2.1-2.34)^2+(1.9-2.34)^2 and divide all of that by n-1=6. This will give you the variance...and then just take the square root to get the standard deviation.
jesus Christ thank u
how do u find the "square difference from each of these points" i was lost after that, >"
go see his video on standard deviation and variance. he explains it more in depth
Redone and better. Keep on going.
@6:32 you made it clear that it is the sampling distribution of sample means (and not simply the sample distribution), then how come is the sample mean at the centre? Isn't the population mean at the centre of sampling distribution of sample mean? Please Clarify, TIA
He uses the sample mean to estimate the population mean. That's the best we can do. Then, using that polulation mean, we compute the confidence interval where we have 95% possibility that the actual population mean is within that confidence interval around the estimated mean.
@@yuzhe6054 but the central value in a sampling distribution of means is always the population mean. I mean shouldn't the confidence interval be constructed around some other point on the graph, say to the right of the centre where our sample mean is located
@@shreyachawla988 Yea, there are chances that the sample mean is not close to the actual population mean. But that's the best we can get. If we want to skewed the centre of the sampling distribution, we won't know which way to skewed the mean, left or right, solely based on the sample we get. To play it safe, we just estimate the population mean with the sample mean and construct the confidence interval around that centre.
@@yuzhe6054 so the normal graph where you are taking sample mean at the centre is the sampling distribution of mean or the sample distribution?
@@shreyachawla988 It's the sampling distribution of the sample mean.
2:20 est SD w/n
Interesting that this has a distinct name. We could just assume nothing about the initial distribution and proceed with the central limit theorem as usual :)
Great as always..
I am taking chyawanprash twice a day, everyday, to understand statistics..
Plz. Make a vedio on "sufficiency or sufficient estimator".
can you apply this method to proportions rather than means?
Does anyone have a link to this T table? I can't find one like this and i really enjoy how it looks
I thougth the t value gave the area not number of deviations from the mean.?
You can calculate the standard deviation of the samples by using the given numbers and mean. In other words, it is S. Why do we have to estimate the standard deviation of population as S, but then calculate the sample standard deviation as S/sqrt(n) ? why not the other way ?
@smallbighorn Hi, If you take the square root of 1.08..you get 1.04
I worship you
Tea tables. I'm thirsty now.
I just want to say, "Whoever created statistics is pure evil!" I have to take headache medications after watching tutorials and trying to figure out the problems still long after the video has ended, sigh..
Kiiikikikikikiiii.
You killed me lol.
I feel the same way, I still dont understand. Sigh toooo
I need to know how you calculated standard deviation because I tried and did not get the same number. Need to quit assuming that people already know how to do part of the problem.
Old comment, but for those seeing it now, Khan Academy takes things step by step, and if they showed you how to do every calculation like standard deviation and mean in every video then the videos would be too long. They did previous videos on stdev and mean which you can go back and watch if you don't understand.
I still don't get it.
What if you don't have a t table and it's asking what the 95% interval is? You go as far as you can and the answer is 0.39?
Ok my existence is the average of random processes
Why did he use a t-able vs a z table?
I got 1.0862 for the sample standard deviation. How did you get 1.04?
Just take sqrt of it , u have found the variance .
if you still need the explanation after 10 years, i can explain it lol
I am still trying to figure out why the initial distribution is normal
DONT SKIP STEPS WHY YOU GOTTA BE LIKE THAT
What's the probability that the instructor is going to ramble on, repeat himself multiple times as he writes, and regularly use the wrong words throughout the video?
2.34 is not the sample mean and 1.04 is not the sample SD
This guy speaks so slow i have to speed it up 1.5 times to match normal tempo rate..
good thing there is a speed up button then haha