Answer:
P(x>15) = 0.9656
Step-by-step explanation:
No. of calls received is a poisson random variable with parameter = 6
mean = 6
And the waiting time between the phone calls received is exponentially distributed with parameter m = 1\6.
We need to find the waiting time more than 15 minutes.
1hour= 60 minutes
15 minutes= 0.214 hours.
P(x>x) = e^{-mx)
P(x>0.214) = e^{-0.214\6}
         = 0.9656