, , ,

The mean of a set of numbers is the sum divided by the number of terms.

Factor out of .

Factor out of .

Factor out of .

Factor out of .

Factor out of .

Factor out of .

Factor out of .

Cancel the common factors.

Factor out of .

Cancel the common factor.

Rewrite the expression.

Divide by .

Add and .

Add and .

Add and .

Set up the formula for variance. The variance of a set of values is a measure of the spread of its values.

Set up the formula for variance for this set of numbers.

Simplify the numerator.

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 .

Add and .

Add and .

Add and .

Simplify the expression.

Subtract from .

Divide by .

Approximate the result.

Find the Variance 4 , 12 , 36 , 108