The mean of 50 observations was 39. It was found later that an observation 48 was wrongly taken as 23. The corrected new mean is  Choose the correct answer:
A) 35.2 B) 36.1 C) 36.5 D) 39.1 E) None
Sol.   Therefore correct sum   = ( 39 × 50 + 48 – 23)   = 1975.   Therefore correct mean   = 1975 / 50   = 39.5.   Answer None
<result>E</result>
The mean of 50 observations was 39. It was found later that an observation 48 was wrongly taken as 23. The corrected new mean is