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Finding Standard Deviation "By-Hand"
Using the lists, the calculator can simulate a spreadsheet style
"by hand" computation of standard deviation. 
(see Measures of Dispersion for the FAST way to find standard deviation)
 

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2

 
Problem:  For the data set {10, 12, 40, 35, 14, 24, 13, 21, 42, 30}, find the range, the standard deviation, the variance, and the mean absolute deviation to the nearest hundredth.
 
  Spreadsheet-style solution for standard deviation:
1.
3
Enter the data in L1.
2.
4

Create L2 to be the
deviations, 8.
2nd LIST → MATH #3 mean
Using the quotes (ALPHA +) will create a dynamic situation where L2 will automatically update when L1 changes.
 
3.

Create L3 to be the deviations squared  6.
Again, using the quotes (ALPHA +) will create a dynamic situation where L3 will automatically update when L2 changes.
 

 

4.
7
From the HOME screen.
Compute the sum of the squared deviations, divide by the number of pieces of data (for a population form), and take the square root.
2nd LIST → MATH #5 sum
2nd LIST → OPS #3 dim gives the dimension (size) of the list.
  

 

 

 

ANSWER:

population standard deviation
is 11.43

 

9

 

guy

 

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