Let p be the mean of m observations and q be the mean of n observations, where p \le q. If the combined mean of (m+n) observations is c, then which one of the following is correct?

  1. A. c \le p
  2. B. c \ge q
  3. C. p \le c \le q
  4. D. q \le c \le p

Correct Answer: C. p \le c \le q

Explanation

The combined arithmetic mean c of two datasets is a weighted average of their individual means p and q. Therefore, c must always lie between p and q. Given p \le q, it holds that p \le c \le q.

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