JEE Mains · Maths · STD 11 - 13. statistics
If the variance of the frequency distribution is \(160\) , then the value of \(\mathrm{c} \in \mathrm{N}\) is
| \(X\) | \(c\) | \(2c\) | \(3c\) | \(4c\) | \(5c\) | \(6c\) |
| \(f\) | \(2\) | \(1\) | \(1\) | \(1\) | \(1\) | \(1\) |
- A \(5\)
- B \(8\)
- C \(7\)
- D \(6\)
Answer & Solution
Correct Answer
(C) \(7\)
Step-by-step Solution
Detailed explanation
\(x\) \(C\) \(2C\) \(3C\) \(4C\) \(5C\) \(6C\) \(f\) \(2\) \(1\) \(1\) \(1\) \(1\) \(1\) \(\bar{x}=\frac{(2+2+3+4+5+6) C}{7}=\frac{22 C}{7}\) \( \operatorname{Var}(\mathrm{x})=\frac{\mathrm{c}^2\left(2+2^2+3^2+4^2+5^2+6^2\right)}{7} \) \( -\left(\frac{22 c}{7}\right)^2 \)…
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