2016 · Q15
Four quantities are such that their arithmetic mean (AM) is the same as the A.M of the first three quantities. The fourth quantity is
General Mental Ability, Quantitative Aptitude and StatisticsElementary statistics
- ASum of the first three quantities
- BA.M of the first three quantities
- C(Sum of the first three quantities)/4
- D(Sum of the first three quantities)/2
Explanation
Let the first three quantities sum to S and the fourth be q. Then (S + q)/4 = S/3, so 3S + 3q = 4S, giving q = S/3 — exactly the arithmetic mean of the first three quantities. Hence (B).