For 10 observations , if and , then their standard deviation is :
- (A)2
- (B)
- (C)
- (D)3✓ Correct
Answer: (D)
Solution
Expanding, gives , and gives . Subtracting, , so and then . With , the variance is . The standard deviation is .
JEE Main · 2026 · 04 Apr 2026 · Shift 2 · Single correct option