16
No. 8 to 9 is proportional to 16 to 18, not 18 to 16.
16/18 = 8/9
((18 * 16) / 9) - 8 = 24.
That's the same as 8/9 x 18/9 = 144/81 = 16/9 or 1 and 7/9
8/9
2/3 x 9/16 = 3/8
Yes, 16/18 = 8/9
9
9 + 8 + 16 + 17 + 18 = 68
8/9 = 16/18
The ratio for 18/16 would be 9:8.