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PLEASE SHOW EACH AND EVERY STEP! THANK YOU!! Emilio, the owner of Pepe Delgados,

ID: 3209277 • Letter: P

Question

PLEASE SHOW EACH AND EVERY STEP! THANK YOU!!

Emilio, the owner of Pepe Delgados, is interested in taking a more statistical approach to predicting customer load. He begins the process by gathering data on the number of arrivals in five-minute intervals. The data below represent the arrivals in five-intervals between 7:00p ans 8:00p every Saturday for three weeks. Assume that arrivals are Poisson distributed. The questions that follow pertain to the 7:00p to 8:00p time period, (adapted from [Black 2012]) a. Compute lambda using the data from all three weeks as one data set. b. What is the probability that no customers arrive during any five-minute interval? c. What is the probability that six or more customers arrive during any five-minute interval? d. What is the probability that during a 10-minute interval fewer than four customers arrive? e. What is the probability that no customers arrive during any 10-minute interval? Compare with part b. f. What is the probability that exactly eight customers arrive in any 15-minute interval?

Explanation / Answer

Solution

Back-up Theory

If X = number of arrivals in a 5-minute interval, follows a Poisson Distribution with parameter , then

P(X = x) = (e-)(x)/(x!),where is the mean arrival rate per 5 minutes……………..(1)

If X = number of arrivals in a 5-minute interval, follows a Poisson Distribution with parameter , and Y = number of arrivals in a 10-minute interval, then

Y follows a Poisson Distribution with parameter 2 [note: 10 = 2x5]………………………………..(2)

Note: all probabilities are obtained by using Excel Function

Now, to work out the solution,

Part (a)

From the given data, mean arrival per 5 minute interval = 108/36 = 3.

So, = 3 ANSWER

Part (b)

Probability of no customer arrival in any 5-minute interval = P(X = 0) = e-3

= 0.0498 ANSWER

Part (c)

Probability of 6 or more customer arrivals in any 5-minute interval = P(X 6)

= 1 – P(X 5) = 1 – 0.9161 = 0.0839 ANSWER

Part (d)

Probability of fewer than 4 customer arrivals in any 10-minute interval = P(X 3/ = 6) [vide (2) under Back-up Theory]

= 0.2851 ANSWER

Part (e)

Probability of no customer arrival in any 10-minute interval = P(X = 0/ = 6) [vide (2) under Back-up Theory]

= 0.0025 ANSWER

Part (f)

Probability of exactly 8 customer arrivals in any 15-minute interval = P(X = 8/ = 9) [vide (2) under Back-up Theory]

= 0.1318 ANSWER