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Hello,
I hope somebody can give me a hint for this problem.
A set of telephone connections should be installed in order to connect the cities A and B. City A has 2000 telephones. If every user of city A gets a direct connection to city B, 2000 lines would be needed, which is extremely wasteful.
We assume that each user in city A needs a telephone connection to city B for two minutes on average during the 10 hours working hours (8.00-18.00) and that these calls are completely random. What minimal number M of telephone connections to city B is needed in order to ensure that not more than 1% of the calls from city A to city B do not get a direct line.
(Instruction: The sum of the probabilities for occupied lines, which is higher than the number of lines, should
be less than 1%. Approximate the probability function by a Gaussian distribution.)
Table of Gaussian Distribution is given.
I have absolutely no clue how to approach this problem. But here's what I got so far:
In the ideal case, i.e. each user is followed by another one:
If every user needs the telephone line for 2 minutes, then that means that we need total 4000 minutes of idle telephone lines. 10 hours are 600 minutes therefore 1 line can be used for 600 minutes. Therefore we need on average 4000 minutes / 600 minutes of lines = 6.6 lines.
I don't know how to proceed from here. He wants use to approximate the probability function by a Gaussian distribution. I am not sure what should be the y and x-axis of this probability function. Should the x-axis of Gaussian distribution be the number of occupied lines and y the probability that this number of lines are occupied.
Please help me
I hope somebody can give me a hint for this problem.
Homework Statement
A set of telephone connections should be installed in order to connect the cities A and B. City A has 2000 telephones. If every user of city A gets a direct connection to city B, 2000 lines would be needed, which is extremely wasteful.
We assume that each user in city A needs a telephone connection to city B for two minutes on average during the 10 hours working hours (8.00-18.00) and that these calls are completely random. What minimal number M of telephone connections to city B is needed in order to ensure that not more than 1% of the calls from city A to city B do not get a direct line.
(Instruction: The sum of the probabilities for occupied lines, which is higher than the number of lines, should
be less than 1%. Approximate the probability function by a Gaussian distribution.)
Homework Equations
Table of Gaussian Distribution is given.
The Attempt at a Solution
I have absolutely no clue how to approach this problem. But here's what I got so far:
In the ideal case, i.e. each user is followed by another one:
If every user needs the telephone line for 2 minutes, then that means that we need total 4000 minutes of idle telephone lines. 10 hours are 600 minutes therefore 1 line can be used for 600 minutes. Therefore we need on average 4000 minutes / 600 minutes of lines = 6.6 lines.
I don't know how to proceed from here. He wants use to approximate the probability function by a Gaussian distribution. I am not sure what should be the y and x-axis of this probability function. Should the x-axis of Gaussian distribution be the number of occupied lines and y the probability that this number of lines are occupied.
Please help me