Step-by-step explanation:
Percentage abundance of Iridium-191 = 37.58 %
Mass of Iridium-191 = 191 amu
Percentage abundance of Iridium-193 = 62.42 %
Mass of Iridium-193 = 193 amu
We need to find atomic mass of Iridium.
Atomic mass of Iridium = 0.3758 x 191 + 0.6242 x 193
Atomic mass of Iridium = 192.25 amu
Atomic mass of Iridium is 192.25 amu