Question 1127379
This is a Poisson distribution with parameter 4.  It is Poisson, because number of calls is proportional to time, discrete, and could theoretically be infinite

From the table
for 4 it is 0.1954
that is e^(-4)*4^4/4!
For 2 or fewer it is 0.2381
Greater than 9, it is 0.0081