# Find the Standard Deviation 10 , 12 , 15 , 18 , 11 , 13 , 14 , 16 , 19 , 20 , , , , , , , , ,
Find the mean.
The mean of a set of numbers is the sum divided by the number of terms.
Simplify the numerator.
Cancel the common factor of and .
Factor out of .
Cancel the common factors.
Factor out of .
Cancel the common factor.
Rewrite the expression.
Divide.
Simplify each value in the list.
Convert to a decimal value.
Convert to a decimal value.
Convert to a decimal value.
Convert to a decimal value.
Convert to a decimal value.
Convert to a decimal value.
Convert to a decimal value.
Convert to a decimal value.
Convert to a decimal value.
Convert to a decimal value.
The simplified values are .
Set up the formula for sample standard deviation. The standard deviation of a set of values is a measure of the spread of its values.
Set up the formula for standard deviation for this set of numbers.
Simplify the result.
Subtract from .
Raise to the power of .
Subtract from .
Raise to the power of .
Subtract from .
Raise to the power of .
Subtract from .
Raise to the power of .
Subtract from .
Raise to the power of .
Subtract from .
Raise to the power of .
Subtract from .
Raise to the power of .
Subtract from .
Raise to the power of .
Subtract from .
Raise to the power of .
Subtract from .
Raise to the power of .
Subtract from .
Divide by .
The standard deviation should be rounded to one more decimal place than the original data. If the original data were mixed, round to one decimal place more than the least precise.
Find the Standard Deviation 10 , 12 , 15 , 18 , 11 , 13 , 14 , 16 , 19 , 20     