NDA2021MathematicsStatisticsActual
The average of a set of 15 observations is recorded, but later it is found that for one observation, the digit in the tens place was wrongly recorded as 8 instead of 3 . After correcting the observation, the average is
Options
- Areduced by 1 3
- Bincreased by 10 3
- Creduced by 10 3
- Dreduced by 50
Correct answer
C. reduced by 10 3
Step-by-step solution
Sum of 15 observations =15 A (where A is average) Reduce in value after correction. 8 x-3 x=50 where x= unit digit of wrong number Reduction in new average = 50 15 = 10 3