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Let the six numbers a 1 , a 2 , a 3 , a 4 , a 5 , a 6 be in A.P. and a 1 + a 3 = 10. If the mean of these six numbers is 2 19 and their va riance is  2 , then 8  2 is equal to:

1. 200
2. 105
3. 220
4. 210

Correct answer: 210

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