#sample standard deviation

How do we compute standard deviation? 

We use

where s is the sample standard deviation (what we want to find), X is your numbers / samples / values, X with a bar is the sample mean, and n is your amount of samples. 

I’ll break it up into steps for you:

1. find the sample mean. Mean = X with a bar = (sum of all values)/(amount of values) 

2. compute (X - X with a bar)^2 for each of your numbers / samples / values

3. sum all (X - X with a bar)^2 

4. divide by n - 1

5. take the square root

Please let us know if you have a more detailed question or want an example! Try it, it’s not too difficult.