Jeff Miller

GMAT OFFICIAL GUIDE DS – A scientist recorded the number of eggs…

A scientist recorded the number of eggs…

Solution:

We are asked to determine the standard deviation of the number of eggs in 10 nests.

Statement One Alone:

The average (arithmetic mean) number of eggs for the 10 nests was 4.

Knowing only the average of the number of eggs for the 10 nests is not enough information to determine the standard deviation. Statement one is not sufficient to answer the question. We can eliminate answer choices A and D.

Statement Two Alone:

Each of the 10 nests contained the same number of eggs.

Since we know that each nest had the same number of eggs, we know that the standard deviation must be zero.

Answer: B