Statisticsmedium · Past Paper
If the mean of a, b, c is M, and (a+b+c+d)/4 = M, then d must be:
A0
BM
C2M
DM/2
✓ Correct Answer: B — M
Since (a+b+c) = 3M, then (3M + d)/4 = M implies 3M + d = 4M, so d = M.
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