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Why do you need a measure of Variability?
Home Introduction to the Standard Deviation Why do you need a measure of Variability? Measuring the Average Distance to the Mean Variability Quiz Population versus Sample Standard Deviation Standard Deviation Calculation Standard Deviation Calculation Short-Cut Method The Standard Deviation with Excel and The Online Calculator Standard Deviation in Practice Standard Deviation QuizView All Tutorials
 Variability Quiz
The Standard Deviation :: Measuring the Average Distance to the Mean


Things to remember:
  1. The range is the maximum minus the minimum value.
  2. You can't just take the average distance to the mean: negatives and positives cancel each other out.
  3. Converting the negatives to positives and then taking the average is the MAD: mean absolute deviation--not used frequently.
  4. Squaring the distances to the mean then taking the average provides the variance. An important measure used often, just not easy to interpret.
  5. Taking the square root of the variance provides the standard deviation.

 
Why do you need a measure of Variability?
Home Introduction to the Standard Deviation Why do you need a measure of Variability? Measuring the Average Distance to the Mean Variability Quiz Population versus Sample Standard Deviation Standard Deviation Calculation Standard Deviation Calculation Short-Cut Method The Standard Deviation with Excel and The Online Calculator Standard Deviation in Practice Standard Deviation QuizView All Tutorials
 Variability Quiz

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October 25, 2017 | Gerald wrote:
overall a very good lesson and well produced video
 
May 13, 2014 | Larry Chuck wrote:
Wut?
 
September 4, 2010 | Tom wrote:
Flash movie is not playing for me. :(
 
June 9, 2009 | ashish jain wrote:
amazing amazing
 
May 5, 2009 | Stephanie Christians wrote:
Woo-hoo! I now finally understand the difference b/t the variance and the standard deviation! Thank you!