In CSMA/CD, what is the term for the fixed unit of data

What value should come in the place of (?) in the following number series?

5670, 1620, 540, 216, 108, ?

What will come in place of the question mark (?) in the following series?

15, 90, 450, ?, 5400, 10800 

4, 9, 24, 69, ?, 609

What will come in place of (?) question mark in the given number series.

12, 27, 44, 65, ?, 139

11       16       42       141       ?      2945      17700

18      29      16      31      ?      33

In each of the following number series, one term is missing. Find the missing term.

5, 7, 12, 22, 39, 65, ?

What will come in place of the question mark (?) in the following series?

72, 108, 172, ?, 416, 612

254, ?, 1022, 1150, 1214, 1246

5, 6, 14, 45, ?, 925