How Do You Calculate Mass Percent of Compounds in a Mixed Sample?

[annayn]

A sample containing NaCl, Na2SO4, and NaNO3 gives the following elemental analysis: Na:32.8%; O: 36.01%; Cl:19.51%.
Calculate the mass percent of each compound in the sample

 

[Lyuokdea]

Try starting by calculating the mass percents for a pure sample of each of the three compounds.

~Lyuokdea