The average of 11 numbers is 10.8. If the average of the first six numbers is 10.5 and that of the last six numbers is 11.4, then the middle number is
Choose the correct option:
A) 71.5  B) 11.5  C) 81.5  D) 11.5  E) 12.6
Explanation:   Middle numbers = [(10.5 x 6 + 11.4 x 6) - 10.9 x 11] = 12.6.   Answer 12.6
<result>E</result>
The average of 11 numbers is 10.8. If the average of the first six numbers is 10.5 and that of the last six numbers is 11.4, then the middle number is