I've attached the problem statement, and used R to find these probabilities. I got to part b, and my probabilities aren't decreasing however, so I'm wondering what I did wrong if anyone can see it.
n=10
> r<-1- pchisq(45,9)
> (36*r)/9
[1] 3.690651e-06
n=25
> r<- 1-pchisq(45,24)
> (36*r)/24
[1] 0.008737591
n=50
> r<- 1-pchisq(45,49)
> (36*r)/49
[1] 0.4672508