Question

The table below shows the monthly balances a person had on their credit card over a five-month period.

Month Balance
January -$50
February $25
March -$70
April -$45
May $25


What was the average monthly balance over the five-month period? Enter your answers and your explanations or work in the space provided.

Answer 1

average monthly balance = $43

Explanation:

If we have a set of N numbers:

{x₁, x₂, x₃, ..., xₙ}

The mean (or average) is calculated as:

Mean = (x₁ + x₂ + ... + xₙ)/N

In this case, the values on the set are the balances for every month.

Then our set is:

{$50, $25, $70, $45, $25}

This is a set of 5 elements.

Then the average monthly balance is:

average monthly balance = ($50 + $25 + $70 + $45 + $25)/5 = $43

average monthly balance = $43