Q73.Let the six numbers a1, a2, . . . , a6 be in A. P. and a1 + a3 = 10 .If the mean of these six numbers is 192 and their variance is σ2 , then 8σ2 is equal to (1) 220 (2) 210 (3) 200 (4) 105
What This Question Tests
This question combines concepts of Arithmetic Progression with mean and variance calculations, requiring finding the common difference and first term of the AP to compute the variance.
Concepts Tested
Formulas Used
nth term of AP: an = a + (n-1)d
Sum of AP: Sn = n/2 * (2a + (n-1)d)
Mean = Σxi / n
Variance σ² = (Σxi² / n) - (Mean)²
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📋 Question Details
- Chapter
- Statistics
- Topic
- Mean and Variance of AP
- Year
- 2023
- Shift
- 24 Jan Shift 2
- Q Number
- Q73
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 9: Sequences and Series; Class 11 Mathematics Ch 15: Statistics
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