The maximum value of that graph is 1 and we can prove this by means of this graph: http://assets.openstudy.com/updates/attachments/4fe27e44e4b06e92b87169f6-syderitic-1340243754047-unt...
50 boys 35 girls 4.40 times 5 is 22+14=36 so all your doing here is 35 times 0.4 because their are 35 girls and you multiple that by 0.4 same thing for the guys anyway answer is 36