answer with explanation

At a telephone exchange, the probability of receiving 16 calls in any time interval of length two minutes is given by the function h(2, k). Assume that the event of receiving k1 calls in a time interval I1 is independent of the event of receiving k2 calls in a time interval I2, for all 161 and k2 whenever the intervals I1 and 12 do not overlap. Find an expression for the probability of receiving 3 calls in 4 minutes in terms of h(2, It). Now suppose h(2, k) is given by 20 Ice2a. h(2, k) = % where a :> 0 is some real number. Now Show that the probability of s 3 4a calls in 4 minutes is given by (4\") e s