What number is missing from the sequence 43.3 26.1 17.5 8.9 0.3?

The answer depends on the position of the missing number.

If it is the first, then it is 86.3.

If the second, then 34.7,

If the third, then 21.8,

If the fourth, then 13.2,

If the fifth, then 0.3 and

if the sixth, then 0.3 (again).