Answer:
a)P= 0.139
b)P(7)= 0.0352
Step-by-step explanation:
Given that
Number of messages per day ,n= 2500
The probability that a message will fail,p=0.005
Here n is much much larger than the P that is why we will use Poisson distribution
In Poisson distribution
Mean ,λ= n p
λ= 2500 x 0.005
λ=12.5
a)
The probability that fewer than 2485 messages reach the base station =P

P= 1 - (P(0)+P(1)+P(2) ----------+P(15))





By solving this
P= 0.139
b)
The probability that 7 of the messages fail to reach the base station=P(7)

P(7)= 0.0352