Three isotopes of argon occur in nature - Ar-36, Ar-38, Ar-40. Calculate the average atomic mass of argon to two decimal places, given the following relative atomic masses and abundances of each of the isotopes: Ar-36 (35.97amu; 0.337%), Ar-38 (37.96amu; 0.063%), and Ar-40 (39.96amu; 99.600%).