Let the total weight of compound is 100 grams
the mass of sodium = 43.38 grams
moles of sodium = mass / atomic mass = 43.38/ 23 = 1.88
mass of carbon = 11.33 grams
moles of carbon = mass / atomic mass = 11.33/12 = 0.944
mass of oxygen = 45.29
moles of oxygen = mass / atomic mass = 45.29 / 16 = 2.83
Let us divide each moles with the lowest moles to get a ratio of whole number
moles of sodium = 1.88/0.944 = 2
moles of carbon = 0.944/0.944 = 1
moles of oxygen = 2.83/0.944 = 3
so the empirical formula is Na₂CO₃