What is the molecular formula for the compound containing 30.4 percent nitrogen and 69.6 percent oxygen by mass and having a molar mass of 92.0 g?

Assume those percentages as mass. Find moles.

30 grams Nitrogen (1 mole N/14.01 grams) = 2.141 moles ( call it 2 )

70 grams oxygen (1 mole O/16.0 grams) = 4.4 moles ( call it 4 )

smallest mole number is 1 in formula and divide larger number by it

2/4 = 2

so..............

NO2

nitrogen dioxide is the empirical formula