A Naturally Occurring Element Consists of Three Isotopes

A naturally occurring element consists of three isotopes. The data for the isotopes are:
Isotope 1: 187.9122 u., 10.861%
Isotope 2: 190.9047 u, ------%
Isotope 3: 192.8938 u, 76.711% What is the average atomic mass of this naturally occurring element? Hint: Percentages should always add up to 100% then find the weighted average.

A) 64.035 u
B) 190.57 u
C) 190.67 u
D) 192.08 u
E) 192.11 u