What amount of Sodium phosphate should have produced

Question

A student produced 109.6 grams of sodium phosphate during neutralization reaction and determined that her percent yeild in the reaction was 64.3%

Answer 1

So, 64.3% of what value is equal to 109.6 grams?

0.643 x = 109.6

x = 109.6/0.643

x = 170.5 grams (to 4 significant figures)