The actual GV ratio is rounded off to .78:1 but is actually =1/(1+(22/77)) or .77778:1.
GV also allows creating 2 intermediate gears by engaging it in 1st or 2nd.
For a 727 this makes:
1st 2.45:1
1st + GV 1.91:1
2nd 1.45:1
2nd + GV 1.13:1
3rd 1.00:1
OD .778:1

Boffin Emeritus