Question

What is the average of the first nine prime numbers?

• A. $11\frac{1}{9}$
• B. $77$
• C. $85$
• D. $410$

Answer 1

Answer: (A)

$11\frac{1}{9}$

The first nine prime numbers are $2,3,5,7,11,13,17,19,23$.

We know, Mean/Average is given by,

$\text{Mean/Average}=\frac{\text{Sum of the elements}}{\text{Total number of elements}}$.

Here, number of observations $=9$.

Therefore, required average $=\frac{2+3+5+7+11+13+17+19+23}{9}=\frac{100}{9}=11\frac{1}{9}$.

Hence, option $A$ is correct.