The naturally occurring isotopes of potassium are potassium-39, potassium-40, and potassium-41. Potassium-39 has an abundance of 93.258% and a mass of 38.964 amu. Potassium-40 has an abundance of 0.011710% and a mass of 39.964 amu. Potassium-41 has an abundance of 6.7302% and a mass of 40.962 amu. Calculate the average atomic mass of potassium