Statisticsmedium · Past Paper
If the mean of 10 observations is 20 and another 10 observations is 30, the combined mean is:
A25
B20
C30
D50
✓ Correct Answer: A — 25
Combined mean = (n1*x1 + n2*x2) / (n1 + n2) = (200 + 300) / 20 = 25.
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