What is the relative density by air of nitric oxide 4?

It is necessary to calculate the relative density of nitrogen oxide 4 by air, for this we use the following formula:
D (N2) air = M (NO2) / M (air)
that is, it is necessary to divide the molar mass of tetravalent nitrogen oxide by the molar mass of air, the result is the following solution:
Calculate the molar mass of nitric oxide
M (NO2) = 14 + 2 × 32 = 46 g / mol
Next, we find the molar mass of air
M air = 29 g / mol
We calculate and get the following value:
M (N2) air = 46 g / mol ÷ 29 g / mol = 1.6 g / mol