JEE MATHEMATICS MCQ: STATISTICS

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The average marks of 10 students in a class is 60 with standard deviation 4 while the average marks of other 10 students is 40 with standard deviation 6 . If all the 20 students are taken together, their standard deviation will be

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Correct option: D

\sqrt{126}

Option D (

\sqrt{126}

) is correct because it's calculated by combining the data from both groups of students, finding the overall mean, and then calculating the combined standard deviation.

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\bar X,

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