Question 1085112
This would be a Poisson distribution with mean 4 for a half hour
Therefore,
c=4 people
d=4 people^2, since Poisson has mean=variance.
Probability of 7 is e^(-4)*4^7/7!=0.0595
probability of 0 clients is e^(-4)=0.0183
1-0.0183=0.9817; this is the probability of at least 1 client.