Answer:
0.048 is the probability that more than 950 message arrive in one minute.
Step-by-step explanation:
We are given the following information in the question:
The number of messages arriving at a multiplexer is a Poisson random variable with mean 15 messages/second.
Let X be the number of messages arriving at a multiplexer.
Mean = 15
For poison distribution,
Mean = Variance = 15

From central limit theorem, we have:
where n is the sample size.
Here, n = 1 minute = 60 seconds
P(x > 950)
Calculation the value from standard normal z table, we have,

0.048 is the probability that more than 950 message arrive in one minute.