Studying Variance

Home Up

 

Enter a list of numbers in L1.
Find the average of the list using the 1-var stats  

From the homescreen press STAT.  Move to the column entitled CALC

Select 1-Var Stats

Press ENTER to view the stats. 

 
Move to the top of List 2 and type L1 - (The mean) 

 

Notice that some of the number are negative, zero and positive. 

 
Move to the top of L2 again and type L22

 

Press ENTER

 
Again return to the homescreen and type 1-var Stats L2. 

Notice the sum of L2.  The average square difference can be found by dividing the sum by the number of items in L2.

Finally take the square root of this average.

This number is the average of the square of the difference of each number from the mean.  It describes how numbers in a list compare to the mean.