Posted by Anna on Saturday, January 9, 2010 at 12:13pm.
I need to know the standard deviation and how to get it for the following set of numbers. {10, 11, 10, 12, 11, 10, 11, 11, 12, 13, 11, 10, 14}

Math  Marth, Saturday, January 9, 2010 at 4:09pm
The standard deviation is the sqrt(sum(mean  i)^2 / (n1)), where i takes on the value of each element in the set, and n is the number of elements in the set.
Start by finding the mean. Then for each element in the set, find the difference from the mean and square it. Find the sum of those differences, divide it by (n1), and take the square root. 
Math  PsyDAG, Sunday, January 10, 2010 at 5:57pm
In case you didn't understand Marth's directions, you need to find the sum of those squared differences.
Since the mean of any distribution is a fulcrum, the sum of the differences of individual scores from the mean always = 0.
I hope this helps a little more.