The arithmetic mean of a group of 75 observations was calculated as 27. It was later found that one observation was wrongly read as 43 instead of the correct value 53. Obtain the correct arithmetic mean of the data.
26.13
27.13
28.13
25.13
Explanation:
Difference=53-43=10 should be increase
New average=27+$\dfrac{10}{75}$
= 27.13