t Tests for One Mean: An Example

An example of a t test on one population mean. I first work through an example of a t test, then briefly investigate the influence of 3 outliers on the conclusions.

The sleep misperception index data is simulated data with the same summary statistics as found in:

Manconi et al. (2010). Measuring the error in sleep estimation in normal subjects and in
patients with insomnia. Journal of Sleep Research, 19:478--486.

[jbstatistics]

You're welcome, and thanks for the compliment! I'm very glad to be of help.

[TheSevenofMine]

Really great video, thanks!
But "usually we can use a statistic software" --> not if you're a student and you've got to do it *all* yourself, meaning in the exam we'll get a t-table, a z-table, a quantile F-distribution, chi-squared table, a table with tolerance limits, ...

[vishalahuja]

Around 3:21, you say that since the sample size is large, the normality assumption is not that important. Can you please explain that?

[dmw]

This video is so f***ing good... Even helps me with my Masters Degree :D Always getting back to it

[thypham]

Your videos are amazing! Thanks a lot. Can I ask what kind of softwares do you use to calculate?

[udriss]

Hy.
But in this actual video at 05:42, you say it's the area BEFORE (to the left) the t-value.
How do you choose between "BEYOND" and "BEFORE" when it's two-sided test ?

[IMADETHISACCFORRAY]

I'm not sure if you will reply, but I'm curious if there is any way to calculate this using some tool in Excel?
I realize that if you have two samples you can perform a t-test, but say if I wanted to apply these numbers given in this video and calculate the answer with excel?
The table in my book doesn't have enough variety in the degrees of freedom and such.

[gardenmenuuu]

sir please answer me/which software u used to write on board

[panagiotisgoulas]

Why if the test statistic is one the left side of the distribution the real mean is on the left side of the distribution then the true mean is less than 0 and not more?