Q68.Let the mean of 50 observations is 15 and the standard deviation is 2 . However, one observation was wrongly recorded. The sum of the correct and incorrect observations is 70 . If the mean of the correct set of observations is 16 , then the variance of the correct set is equal to (1) 10 (2) 36 (3) 43 (4) 60
What This Question Tests
This question involves correcting the mean and variance of a dataset when a single observation is found to be incorrect, requiring careful application of statistical formulas for sum and sum of squares.
Concepts Tested
Formulas Used
Mean = (Σxi)/n
Variance = (Σxi^2)/n - (Mean)^2
Standard Deviation = sqrt(Variance)
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📋 Question Details
- Chapter
- Statistics
- Topic
- Mean and Standard Deviation
- Year
- 2022
- Shift
- 26 Jun Shift 2
- Q Number
- Q68
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 15: Statistics
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