JEE Mains · Maths · STD 11 - 13. statistics
The mean and standard deviation of \(15\) observations were found to be \(12\) and \(3\) respectively. On rechecking it was found that an observation was read as \(10\) in place of \(12\) . If \(\mu\) and \(\sigma^2\) denote the mean and variance of the correct observations respectively, then \(15\left(\mu+\mu^2+\sigma^2\right)\) is equal to ...........
- A \(2521\)
- B \(3562\)
- C \(1245\)
- D \(2356\)
Answer & Solution
Correct Answer
(A) \(2521\)
Step-by-step Solution
Detailed explanation
Let the incorrect mean be \(\mu^{\prime}\) and standard deviation be \(\sigma^{\prime}\) We have \(\mu^{\prime}=\frac{\Sigma x_i}{15}=12 \Rightarrow \Sigma x_i=180\) As per given information correct \(\Sigma x_i=180-10+12\)…
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