Question 1105340
The first is 50C32*0.6^32*0.4^18.  This is 0.0987
The second uses the mean and sd of 30 (np) and  variance 12 (np*(1-p)) so sd is 3.46 (sqrt var)
using continuity correction factor want z=(31.5-30)/3.46 or +0.4335.  This probability is 0.3323.
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c)  This is 0.25*0.75=0.1875.
d) If one uses the Poisson (I would probably use the binomial, since the probabilities would be known) the parameter is 16 and 20 is wanted. Therefore, lambda is 16 and x is 20.
e^(-16)*16^20/20!=0.0559