Let X be a (data) set, we partition the data $A, B \subset X $ such that A and B are disjoint $(A \cap B = ∅ \ and \ A \cup B = X)$.
Mean(A) = 5
Mean(B) = 10
what is the Mean(X)?
1) Is the answer $5 \le Mean(X)\le 10?$
2) Also what if $ A \cup B \ne X$
It was on an SAT question where they said: there is a group, where the mean for women was N and mean for men was M, where N and M are numbers (we will assume N< M) but don't remember what they actually were. What is the mean for the whole group? I think I remember the answer key saying that it was $N \le Mean(X)\le M?$