Once we get the mole ration we get what we call the emprical formula which will be

C1 I 1.5

now to get the molecular formula we we get a constant n which when multuplid by the molar masses of atoms in empirical formula will give us the molecular weight

(C1 I 1.5)n = 809.44

molar mass of C = 12

MOLAR mass of I = 126.9

thus replacing in above equation we get

(12)n + 12.96*1.5*n = 809.44

12n + 190.35n = 809.44

n = 809.44/202.35

n= 4

once we get n we multiply the emprical formula by n to get molecular formula