Answer: The length of an interval of time is 0.02 seconds.
Step-by-step explanation:
Since we have given that
mean rate = 16 per hour
Probability that no messages arrive during this interval = 0.78
Let X be the Poisson distribution with parameter [tex]\lambda=16[/tex]
[tex]P(X=0)=0.78=e^{-\lambda T}=e^{-16T}\\\\\text{Taking log on both the sides}\\\\\ln 0.78=-16T\\\\\dfrac{\ln 0.68}{-16}=T\\\\T=0.0155[/tex]
Hence, the length of an interval of time is 0.02 seconds.