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JEE Main Math Class 12 Statistics Part 1 Questions

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Question : 8

Total: 115

Let the mean and standard deviation of marks of class A of 100 students be respectively 40 and α(>0), and the mean and standard deviation of marks of class B of n students be respectively 55 and 30−α. If the mean and variance of the marks of the combined class of 100+n students are respectively 50 and 350 , then the sum of variances of classes A and B is:

[31-Jan-2023 Shift 2]

500
650
450
900

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