Q86.The mean and standard deviation of 15 observations are found to be 8 and 3 respectively. On rechecking it was found that, in the observations, 20 was misread as 5 . Then, the correct variance is equal to _____.
What This Question Tests
This question tests the ability to correct the mean and variance of a dataset when one observation is misread, requiring recalculation of sum and sum of squares.
Concepts Tested
Formulas Used
Mean: Σxi / n
Variance: (Σxi^2 / n) - (Mean)^2
📚 NCERT Sections This Tests
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📋 Question Details
- Chapter
- Statistics
- Topic
- Mean and Standard Deviation
- Year
- 2022
- Shift
- 28 Jun Shift 1
- Q Number
- Q86
- Type
- Numerical
- NCERT Ref
- Class 11 Mathematics Ch 15: Statistics
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