I am having difficulty with calculating the mol ratio of argon (MW 39.95) to nitrogen (28.01) if the calculated MW is 28.15. This problem is taken from Zumdahl's Chemical Principals 2nd Ed. (Chapter 5 #29) and the answer is given at the back of the book as 1.18 X 10^-2. Can someone nudge me in the right direction on how to arrive at this response? Thanks!