Your Answer is

Correct Answer is G

Explanation

The difference between item 10 and item 6 is 5, indicating that the tolerance is 1.25. Then the first item is 8-(6-1)×1.25=1.75, and the fourth item is 8-(6-4)×1.25=5.5. Then the sum of the first 4 items is (1.75+5.5)×4÷2=14.5. Therefore choose G.