Mathematics · 2019
JEE Main · 10 April 2019, Shift 2 · Q86
If both the mean and the standard deviation of 50 observations x_1, x_2, …, x_50 are equal to 16, then the mean of (x_1-4)^2,(x_2-4)^2, …..,…
If both the mean and the standard deviation of $\displaystyle 50$ observations $\displaystyle x_1, x_2, \ldots, x_{50}$ are equal to $\displaystyle 16$, then the mean of $\displaystyle \left(x_1-4\right)^2,\left(x_2-4\right)^2, \ldots . .$, $\displaystyle \left(x_{50}-4\right)^2$ is :
Official answer
(2)
$\displaystyle 400$
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JEE Main 2019 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.