Q. Mean of 100 observation is 45. If it was later found that two observations 19 and 31 were incorrectly recorded as 91 and 13. The correct mean is
A) 44
B) 45
C) 44.46
D) 45.54
Explanation
(c)
Total of corrected observations
$= 4500 - (91 + 13) + (19 + 31)$
$= 4446$
$\therefore\ \ Mean = \frac{4446}{100} = 44.46$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.