Q71.If the mean and variance of the following data: 6, 10, 7, 13, a, 12, b, 12 are 9 and 374 respectively, then (a −b)2 is equal to: (1) 24 (2) 12 (3) 32 (4) 16
What This Question Tests
The problem requires applying the definitions of mean and variance for ungrouped data to form a system of equations and solve for the unknown values, then compute the required expression.
Concepts Tested
Formulas Used
Mean (x̄) = (Σxi) / n
Variance (σ²) = (Σx²i / n) - x̄²
📚 NCERT Sections This Tests
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📋 Question Details
- Chapter
- Statistics
- Topic
- Mean and variance of ungrouped data
- Year
- 2021
- Shift
- 27 Jul Shift 1
- Q Number
- Q71
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 15: Statistics
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