The pretend element, knoxium, Kx, has the following composition:
164Kx, 164.08 amu (60.44%)
165Kx, 165.11 amu (13.55%)
169Kx, 168.92 amu (??????%)
What is the average atomic mass of the "knoxium"?

164.08amu
165.48amu
166.04 amu