Q68.Let the mean and the variance of 5 observations x1, x2, x3, x4, x5 be 245 and 19425 respectively. If the mean and variance of the first 4 observation are 27 and a respectively, then (4a + x5) is equal to (1) 13 (2) 15 (3) 17 (4) 18
What This Question Tests
This question assesses the ability to apply the formulas for mean and variance for a set of observations, and then use these to find properties of a subset of observations. It involves algebraic manipulation of statistical definitions.
Concepts Tested
Formulas Used
Mean (x̄) = (Σxᵢ)/n
Variance (σ²) = (Σxᵢ²)/n - (x̄)²
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📋 Question Details
- Chapter
- Statistics
- Topic
- Mean and Variance
- Year
- 2022
- Shift
- 29 Jun Shift 1
- Q Number
- Q68
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 15: Statistics
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