Mathematics · 2021
JEE Main · 25 July 2021, Shift 2 · Q68
The first of the two samples in a group has 100 items with mean 15 and standard deviation 3. If the whole group has 250 items with mean 15.6 and…
The first of the two samples in a group has $\displaystyle 100$ items with mean $\displaystyle 15$ and standard deviation $\displaystyle 3$ . If the whole group has $\displaystyle 250$ items with mean $\displaystyle 15.6$ and standard deviation $\displaystyle \sqrt{13.44}$, then the standard deviation of the second sample is :
Official answer
(4)
$\displaystyle 4$
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JEE Main 2021 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.