Task: Question Answering
Input (English): Problem: the mean of 50 observations was 36 . it was found later that an observation 48 was wrongly taken as 21 . the corrected new mean is : 
Options: a ) 36.54 , b ) 36.58 , c ) 36.23 , d ) 36.14 , e ) 36.81
Output (English): a