What is the standard deviation of {7, 2, 4, 6, 8, 11}?
1 Answer
May 4, 2016
Assuming we are looking for the population standard deviation
Explanation:
The arithmetic steps required:
- Find sum of values
- Find mean (arithmetic average)
- Find deviation from mean for each value (value minus the mean)
- Find square of deviation from mean for each value
- Find the sum of the squares of the deviations
- Find the average of the sum of the squares of the deviations (this is the population variance)
- Find the square root of the average of the sum of the squares of the deviations (this is the population standard deviation)
This could be done manually or in a spreadsheet:
In actual practice most scientific calculators will have a function for calculation of the standard deviation, or, if you are using a spreadsheet, a builtin function (in Excel its STDEVP)