Standard error
на канале: Data Science& AI Learner
In the previous lesson we show that no matter the underlying distribution of the data set to abuse of
the sample means would be normal with a mean equal to the original mean and a variance equal to the
original variance divided by the sample size.
All right.
This lecture will be very short and has the sole purpose of defining what a standard error is.
The standard error is the standard deviation of the distribution formed by the sample means.
In other words the standard deviation of the sampling distribution.
So how do we find it.
We know it's variance.
Sigma squared divided by n.
Therefore the standard deviation is Sigma divided by the square root of n done like a standard deviation.
The standard error shows variability.
In this case it is the variability of the means of the different samples we extracted.
You can guess that since the term has its own name it is widely used and very important.
Why is that important.
Well it is used for almost all statistical tests because it shows how well you approximated the true
mean.
More on that in the next lessons.
Note that it decreases as the sample size increases.
This makes sense as bigger samples give a better approximation of the population.
That's all for now.
Thanks for watching.
@dsailearner
Смотрите видео Standard error онлайн без регистрации, длительностью часов минут секунд в хорошем качестве. Это видео добавил пользователь Data Science& AI Learner 16 Июль 2024, не забудьте поделиться им ссылкой с друзьями и знакомыми, на нашем сайте его посмотрели раз и оно понравилось людям.