Two samples of sodium chloride were decomposed into their constituent elements. one sample produced 6.98g of sodium and 10.7g of chlorine, and the other sample produced 11.2 g of sodium g and 17.3g of chlorine. are these results consistent with the law of definite proportion?

In law of definite proportions, all you need to show is how much one component reacts with another one on a unit weight basis. So let us try it here.

Sample 1: 6.98 g Na reacts with 10.7 g Cl, so 1 g Na will react with 10.7/6.98 = 1.53 g Cl Sample 2: same approach as above, 17.3/11.2 = 1.54 g Cl

So in both samples of NaCl, the sodium reacts with Cl in a definite proportion of 1:1.5 (rounded out).

There you have it.

p. s. you can do these calculations either on per g or per 100 g basis, ratios will remain the same.