Find the mean of the first 9 prime numbers (correct to two decimal places).
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 11.11
The mean is the sum of the values divided by their number. The smallest prime is 2, since 1 is not a prime number.
First 9 primes: 2, 3, 5, 7, 11, 13, 17, 19, 23
Sum \(=2+3+5+7+11+13+17+19+23=100\)
Mean \(\displaystyle=\frac{100}{9}=11.11\) (to two decimal places)
The mean is 11.11.