User blog comment:Tuner King 5/Help plz/@comment-24808864-20160112230745/@comment-24808864-20160112233630

OK, I wrote a short little program on my calculator which could figure out the discrete differences. You would likely have to do these manually to receive credit in a class, but if you were working with the "continuous" model your answer should be close to the same (I would expect, but am not certain).

P(18)-P(19)=0.03216

P(19)-P(20)=0.03227

P(20)-P(21)=0.03221

So I would anticipate that the correct answer to the "continuous" case for this room of 30 people would be somewhere between 19 and 20.