Uploaded May 2013 | Updated September 2026, 1 hour ago
A discussion of the assumptions of the t test on one mean. (The assumptions are the same as those of the t confidence intervals for one mean.) The assumptions are discussed, and the effect of different violations of the normality assumption is investigated through simulation.
(This video is an updated version of an earlier video, updated to correct a typo.)
A discussion of the assumptions of the t test on one mean. (The assumptions are the same as those of the t confidence intervals for one mean.) The assumptions are discussed, and the effect of different violations of the normality assumption is investigated through simulation.
(This video is an updated version of an earlier video, updated to correct a typo.)




![Introduction to the t Distribution (non-technical)
A brief non-technical introduction to the t distribution, how it relates to the standard normal distribution, and how it is used in inference for the mean.
For those that use R, below are the R codes to find the values found in the video.
z value for a 95% interval:
qnorm(.975)
[1] 1.959964
t value for a 95% interval (5 DF)
qt(.975,5)
[1] 2.570582
t value for a 95% interval (10 DF)
qt(.975,10)
[1] 2.228139 Introduction to the t Distribution (non-technical)](https://i.ytimg.com/vi/Uv6nGIgZMVw/mqdefault.jpg)





