1. The problem statement, all variables and given/known data An experiment you're designing needs a gas with γ = 1.49. You recall from your physics class that no individual gas has this value, but it occurs to you that you could produce a gas with γ = 1.49 by mixing together a monatomic gas and a diatomic gas. What fraction of the molecules need to be monatomic? 2. Relevant equations [itex]\gamma[/itex]=5/3 for Monatomic [itex]\gamma[/itex]=7/5 for Diatomic 3. The attempt at a solution [itex]\gamma[/itex]=5x/3+7/5(1-x)=1.49 I solve for x and get 0.3375, but this is wrong. I can't figure out what I'm doing wrong because everywhere I look it seems correct to me.