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The mean and variance of 20 observations are found to be 10 and 4, respectively. On rechecking, it was found that an observation 9 was incorrect and the correct observation was 11. Then the correct variance is :

1. 3.99
2. 3.98
3. 4.01
4. 4.02 CAREER POINT CAREER POINT Ltd., CP Tower, IPIA, Road No.1, Kota (Raj.), Ph: 0744-6630500 www.careerpoint.ac.in 10 JEE Main Online Paper

Correct answer: 3.99

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