JEE Mains · Maths · STD 11 - 13. statistics
The mean and variance of \(5\) observations are \(5\) and \(8\) respectively. If \(3\) observations are \(1,3,5\), then the sum of cubes of the remaining two observations is
- A \(1072\)
- B \(1792\)
- C \(1216\)
- D \(1456\)
Answer & Solution
Correct Answer
(A) \(1072\)
Step-by-step Solution
Detailed explanation
\(\frac{1+3+5+a+b}{5}=5\) \(a+b=16 \ldots \ldots(1)\) \(\sigma^2=\frac{\sum x_1^2}{5}-\left(\frac{\sum x}{5}\right)^2\) \(8=\frac{1^2+3^2+5^2+a^2+b^2}{5}-25\) \(a^2+b^2=130 \ldots \ldots(2)\) \(b y(1),(2)\) \(a=7, b=9\)
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