Answer:
average atomic mass of sulfur = 32.066 amu
Step-by-step explanation:
The average atomic mass is calculated as following:
average atomic mass = fraction of isotope (1) × mass number of the isotope (1) + fraction of isotope (2) × mass number of the isotope (2) + ... + fraction of isotope (n) × mass number of the isotope (n)
average atomic mass of sulfur = (95/100) × 32 + (0.76/100) × 33 + (3.22/100) × 34 + (0.89/100) × 36 = 32.066 amu
(amu - atomic mass units)