The Sample Variance: Why Divide by n-1?

[reidginoza]

I have been looking for this explanation for a long time. It's surprisingly rare given the large number of statistics resources, so I'm especially grateful for your video. Thank you!

[Maha_s]

Perfect - as always! Your explanation zero into the topic and have crystal clear clarity!

[MrVasilist]

You are great in your videos. A simple foundation can help explain the toughest ideas. I am taking a graduate business statistics class and honestly i wish professors used your approach. Instead of getting to technical questions that people dont want or cant understand its better to keep the basics solid and then present the outcomes.

[seg]

There is a logical flaw in the 'degrees of freedom' thing. It requires you to know the sample mean before knowing all the sampled values which is impossible. So you have to sample the very last value to calculate sample mean ( 5 in the video ). Am I missing something?

[thecapedcrusaderr-sq]

What an explanation on lost degrees of freedom when inferring population mean from sample mean. In other words, why calculation of sample variance is divided by n-1 and not n. Hats-off.

[dantedt]

This channel helped me get my Statistics degree. Thank you.

[rijakhalid]

It had been killing me that I did not have a good understanding on n-1. This helped A LOT. Thank you SO SO MUCH

[redangrybird]

This is the best definition for a layman of what are degrees of freedom.
Thanks, take care. ✌😷

[marcellocosta]

This video and the next complete eachother! Thanks for sharing your knowledge with the world, in such a clear and direct way!

[Newascap]

JB > Khan Academy
Thank you very much, sir. Great explanation

[daluvuyojames]

I have been looking for this and the explanation of degrees of Thank you.

[shreyashimukhopadhyay]

Excellent explanation! I couldn’t understand it this clearly previously in under grad.

[我从通化来]

Finally I got a more intuitive understanding of df because of your tutorial... Appreciated

[afrathahamed]

you guys have done a great job by making these kind of useful videos for statistic students
finally i found an amazing side for learning statistic!

[hung]

better explanation than what ive seen in previous video! thank you!

[Rationalist-Forever]

Finally I got this concept. Thank you so much for the clear explanation.

[zhuwenhao]

Only by dividing by n-1 instead of n is s^2 an UNBIASED estimator of the population parameter. It is just a mathematical fact. Good explanation.

[lu]

most clear explanation of degree of freedom ever! thank you

[taniamitra]

Thank you so much for this! I finally understand the intuition :)

[vasishtvemuri]

Just a doubt, even when we have the population mean (mu), the sum of the deviations from the mean must be equal to zero right (in this case the third observation should be 11 making the sum zero). Why is it that we apply this logic only while considering a sample?