Question

You are in a deployed environment serving on an Assessments staff. Over the past year, we have averaged about one mortar attack every three days. The commander responsible for base security comes to see you. He is concerned because over the next week, the base is going to have quite a few VIP visitors from the State Department. As part of the risk assessment for the State Department, he is required to report the probability of experiencing a mortar/rocket attack. He asks you, "What is the probability we get no mortar attacks over the next week while the VIPs are here?

a) Step 1: What kind of problem is this (which distribution applies)?

b) Step 2/3: What are the key elements (parameters of the distribution)?

c) Step 4: What is the unknown element? [P(X=x), P(Xx),…]

d) Step 5: Solve

e) Step 6: Report.

Answer 1

The information provided is,we have on average one mortar attack every 3 days.

Let X be the number of attacks in a particular day.

Therefore,

a) X follows poison distribution wire rate and time interval t=3 days.

b) The probability mass function of a random variable X is given by

; for x>=0

c) The probability that there will be no mortar attacks over the next week is given by

since 0! =1

e) The probability that there will be no mortar attack over the next week is 0.00091

Therefore there is high chances of mortar attacks over the next week.

Therefore the commander must provide high security to the base.