Question

Find the standard deviation for the following data. round your answers to the nearest hundredth.

{11,16,17,20}

Answer 1

Make a table:

Complete the table (the first row is already done for you).
Find the total of the third column, call it T.
The standard deviation of the given population {11,16,17,20} is equal to
sqrt(T/4) (round to the nearest hundredth).

To better understand the concept, read/watch:
https://www.khanacademy.org/math/probability/descriptive-statistics/variance-std-deviation/v/population-standard-deviation

The above calculation is for a population (i.e. we used ALL the data available).
For a sample standard deviation, the equation is different.
Read the following link to understand the difference.
https://www.mathsisfun.com/data/standard-deviation-formulas.html