Q86.If the variance of the frequency distribution 𝑥𝑖 2 3 4 5 6 7 8 Frequency 𝑓i 3 6 16 𝛼 9 5 6 is 3, then 𝛼 is equal to
What This Question Tests
This problem tests the direct application of formulas for mean and variance of a frequency distribution to find an unknown frequency. It involves algebraic manipulation to solve for α.
Concepts Tested
Formulas Used
Mean (μ) = (Σfᵢxᵢ) / (Σfᵢ)
Variance (σ²) = (Σfᵢxᵢ²) / (Σfᵢ) - μ²
📚 NCERT Sections This Tests
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11.6 The threshold frequency for a certain metal is 3.3 × 1014 Hz. If light of frequency 8.2 × 1014 Hz is incident on the metal, predict the cut- off voltage for the photoelectric emission.
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12.5 A hydrogen atom initially in the ground level absorbs a photon, which excites it to the n = 4 level. Determine the wavelength and frequency of photon.
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📋 Question Details
- Chapter
- Statistics
- Topic
- Variance of a frequency distribution
- Year
- 2023
- Shift
- 31 Jan Shift 1
- Q Number
- Q86
- Type
- Numerical
- NCERT Ref
- Class 11 Mathematics Ch 15: Statistics
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