Variance

• The scatter distance

  • Is the distance from the red line

    • For example x6 and x7

• The problem

  • Is that x6 and x7 are on opposite sides

    • And adding them cancels them out

• The solution

  • Is to square the "x" readings

    • To get rid of "minus" signs

• To get a measure of how spread out the scatter is

  • Calculate the average of the squared distances

    • And this is called the "variance" written as s2

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