Jan 27, 2022 · Just before you take the square root you have a number which is called the variance. So if I take your headline literally, the answer to "why do we calculate variance" is …

Oct 26, 2018 · This is the formula for the 'pooled standard deviation' in a pooled 2-sample t test. If we may have two samples from populations with different means, this is a reasonable estimate …

Nov 29, 2020 · You can talk about the standard deviation of random variables. What you have described as a "yes/no question" is not in and of itself a random variable.

This is actually computationally efficient, because you just need to count the number of samples, the sum of the samples, and the sum of the squares of each sample. Once you need to "read" …

Jul 16, 2019 · How do you compute standard deviation on a probability? You don't. There's an alternate definition of z-score for probabilities

Jan 25, 2018 · Calculating standard deviation without a data set. Ask Question Asked 7 years, 11 months ago Modified 3 years, 11 months ago

May 23, 2016 · How do you find the sample standard deviation when given the population standard deviation? What formula do you use? If you can make up an example that would be …

There is. Your alternative formulation of taking the absolute values of the differences instead of squaring them is called the mean absolute deviation (or average absolute deviation). Both the …

For an unweighted sample, calculating the standard deviation of the mean from the standard deviation of the distribution is described on Wikipedia. How do I calculate it for the weighted …

and the updated standard deviation would be just the square root. If you want the population variance or standard deviation replace N-1 with N and N-2 with N-1.