MathBits.com Table of Contents

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)
 


 
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.

Enter the data in L1.
2.

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

 

4.

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

 

 

 


Finding Your Way Around TABLE of  CONTENTS