Standard Deviation
The Standard Deviation is a measure of how spread out numbers are. Its symbol is???(the greek letter sigma) The formula is easy: it is the?square root?of the?Variance Variance = The average of the?squared?differences from the Mean. To calculate the variance follow these steps: Work out the Mean (the simple average of the numbers) Then for each number: subtract the Mean and square the result (the squared difference). Then work out the average of those squared differences. (Why Square?)
Text automatically extracted from attachment below. Please download attachment to view properly formatted document.
---Extracted text from uploads/statistics/standard_deviation.docx---