Question

How do you find the standard deviation of 5.6, 5.2, 4.6, 4.9, 5.7, 6.4?

Answer 1

`.5859`

Explanation:

First, find the mean:

`(5.6+5.2+4.6+4.9+5.7+6.4)/6=5.4`

Now find the sum of the differences between the mean and all the points. Square those results:

`(5.6-5.4)^2=.04`
`(5.2-5.4)^2=.04`
`(4.6-5.4)^2=.64`
`(4.9-5.4)^2=.25`
`(5.7-5.4)^2=.09`
`(6.4-5.4)^2=1`

Find the average of the differences:

`(.04+.04+.64+.25+.09+1)/6=.343`

Now square root the result:

`sqrt(2.06)=.5859`

Answer 2

Using graphing calculator

Explanation:

You can do this problem very easily using a graphing calculator.

First, put the data set in a list. Go to stat, then edit, and then put in your numbers in one column.

Then, go to stat, then calc, then 1 var stats. Plug in your list and press calculate. Your result is `sigmax`