JEE Mains · Maths · STD 11 - 13. statistics
Let the mean and variance of the frequency distribution
| \(\mathrm{x}\) | \(\mathrm{x}_{1}=2\) | \(\mathrm{x}_{2}=6\) | \(\mathrm{x}_{3}=8\) | \(\mathrm{x}_{4}=9\) |
| \(\mathrm{f}\) | \(4\) | \(4\) | \(\alpha\) | \(\beta\) |
- A \(\frac{16}{3}\)
- B \(4\)
- C \(\frac{17}{3}\)
- D \(5\)
Answer & Solution
Correct Answer
(C) \(\frac{17}{3}\)
Step-by-step Solution
Detailed explanation
\(\text { Given } 32+8 \alpha+9 \beta=(8+\alpha+\beta) \times 6\) \(\Rightarrow 2 \alpha+3 \beta=16 \quad \ldots \text { (i) }\) \(\text { Also, } 4 \times 16+4 \times \alpha+9 \beta=(8+\alpha+\beta) \times 6.8\) \(\Rightarrow 640+40 \alpha+90 \beta=544+68 \alpha+68 \beta\)…
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