What is the arithmetic mean (average) of the first 10 natural numbers?

The correct answer is Option (3) → 5.5

The natural numbers start at 1. Numbers that go up by the same step have an average equal to the average of the first and the last number.

• The numbers are 1, 2, 3, …, 10

• \(\displaystyle \text{Average}=\frac{1+10}{2}=5.5\)

The average is 5.5. Starting the count at 0 (whole numbers 0 to 9) would give 4.5, but 0 is not a natural number.