Uploaded October 2012 | Updated September 2026, 2 hours ago
I discuss confidence intervals for a single population variance. The methods used here are based on the assumption of sampling from a normally distributed population (these methods involve the chi-square distribution). The underlying logic behind the form of the interval is discussed, and an example is then worked through.
N.B. There is a typo at 0:36, where the square is missing on the sample variance formula. The sample variance is of course the sum of *squared* deviations from the sample mean, divided by n-1.
I discuss confidence intervals for a single population variance. The methods used here are based on the assumption of sampling from a normally distributed population (these methods involve the chi-square distribution). The underlying logic behind the form of the interval is discussed, and an example is then worked through.
N.B. There is a typo at 0:36, where the square is missing on the sample variance formula. The sample variance is of course the sum of *squared* deviations from the sample mean, divided by n-1.








![An Introduction to Hypothesis Testing
A first look at hypothesis testing.
For those that use R, below is the R code to find the binomial probability given in this video.
To find the probability that X takes on a value that is at least 28, where X has a binomial distribution with parameters n = 100 and p = 1/4:
1-pbinom(27,100,1/4)
[1] 0.2776195
To find the probability that X takes on a value that is at least 44, where X has a binomial distribution with parameters n = 100 and p = 1/4:
1-pbinom(43,100,1/4)
[1] 2.700295e-05 An Introduction to Hypothesis Testing](https://i.ytimg.com/vi/tTeMYuS87oU/mqdefault.jpg)

