Problem in description thanks

Question

I just need to know how to do this problem I don't understand how to set it up so if I could get some help before Monday, September 3rd that would be awesome thank you.

 

A plant fertilizer contains 16 % nitrogen ( N ) by mass. In a container of soluble plant food, there are 13.0 oz of fertilizer. How many grams of nitrogen are in the container?

Answer 1

13.0 oz x (28.3495gram/oz) = 368.54 grams

 

16% by weight means 16g/100g

 

16/100 = x/368.54

 

x = 58.97 g Nitrogen