NTA Abhyas JEE Main2020MathematicsStatisticsPractice
In an experiment with 10 observations on x the following results are available ∑ x 2 = 354 and ∑ x = 58 . If one observation that was 8 was found to be wrong and was replaced by the corrected value 10 , then the corrected variance is
Options
- A5
- B3
- C4
- D6
Correct answer
B. 3
Step-by-step solution
∑ x 2 = 354 , ∑ x = 58 ∑ x ′ = 58 − 8 + 10 = 60 ∑ x ′ 2 = 354 + 100 − 64 = 390 Variance = ∑ x ′ 2 10 − ∑ x ′ 10 2 = 390 10 − 60 10 2 = 39 - 36 = 3