Mathematics · 2023
JEE Main · 25 January 2023, Shift 1 · Q77
The mean and variance of the marks obtained by the students in a test are 10 and 4 respectively. Later, the marks of one of the students is increased…
The mean and variance of the marks obtained by the students in a test are $\displaystyle 10$ and $\displaystyle 4$ respectively. Later, the marks of one of the students is increased from $\displaystyle 8$ to 12. If the new mean of the marks is $\displaystyle 10.2$, then their new variance is equal to :
Official answer
From NTA’s final answer key for this paper.
(4)
$\displaystyle 3.96$
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JEE Main 2023 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.