Mean of 100 observations is 45. It was later found that two observations 19 and 31 were incorrectly recorded as 91 and 13. The correct mean
As learnt in
ARITHMETIC Mean -
For the values x1, x2, ....xn of the variant x the arithmetic mean is given by
In case of discrete data.
-Given that,
But two numbers (19+31 = 50) were incorrect
So, net sum = 4500 - 50 = 4450
Add correct numbers (91+13 = 104)
⇒ 4450 +104 = 4554
⇒ new mean = 4554/100 = 45.54
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