Hi dkumar2012,

This question is based completely on 'Average Formula' rules. If you're comfortable with the math involved, then you'll likely find it easiest to take an Algebraic approach to solving it.

We're told that the average of 7 numbers is 12.2

(Sum of numbers)/7 = 12.2

Sum of numbers = (12.2)(7) = 85.4

Next, we're told that the sum of 4 (of the 7) numbers is 42.8

From this information, we can calculate the sum of the OTHER 3 numbers:

85.4 - 42.8 = 42.6

The question asks for the AVERAGE of the OTHER 3 numbers....

42.6/3 = 14.2

Final Answer:

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n=7, xhat=12.2, sum of 4 numbers = 42,8.

Total=n*xhat=85,4.
The three remaining: 85,4-42,8=42,6.

42,6/3=14,2 = B
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Total of 7 numbers is 12.2*7 = 85.4

Total of 4 numbers is 42.8

So, Total of 3 numbers is 85.4 - 42.8 = 42.6

Average of the 3 numbers is 42.6/3 = 14.2

Hence, answer will be (B) 14.2

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Thanks and Regards

Abhishek....

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