To write as a fraction with a common denominator, multiply by .
Step 2
Combine and .
Step 3
Combine the numerators over the common denominator.
Step 4
Simplify the numerator.
Multiply by .
Subtract from .
Step 5
The mean of a set of numbers is the sum divided by the number of terms.
Step 6
Simplify the numerator.
Write as a fraction with a common denominator.
Combine the numerators over the common denominator.
Add and .
Step 7
Multiply the numerator by the reciprocal of the denominator.
Step 8
Cancel the common factor of .
Factor out of .
Cancel the common factor.
Rewrite the expression.
Step 9
Divide.
Step 10
The mean 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.