,

Rewrite the division as a fraction.

Factor out of .

Cancel the common factors.

Factor out of .

Cancel the common factor.

Rewrite the expression.

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

Write as a fraction with a common denominator.

Combine the numerators over the common denominator.

Add and .

Multiply the numerator by the reciprocal of the denominator.

Multiply and .

Multiply by .

Divide.

Find the Mean (Arithmetic) 1 , 200÷500