The mean and standard deviation of 20 observations are found to be 10 and 2, respectively. On rechecking, it was found that an observation by mistake was taken 8 instead of 12. The correct standard deviation is
- (A)
- (B)1.94
- (C)✓ Correct
- (D)1.8
Answer: (C)
Solution
, and variance .
Correcting : , mean ; .
Correct variance , so SD
Correcting : , mean ; .
Correct variance , so SD
JEE Main · 2024 · 06 Apr 2024 · Shift 1 · Single correct option