Question

60% of a company’s servers are contract managed. About 10% of contract managed servers suffered a security incident and about 30% of the servers not contract managed suffered a security incident. Let C stand for “contract managed”, C’ stand for “not contract managed”, S stand for “suffered a security incident”, and S’ stand for “did not suffer a security incident.” USE PROBABILITY NOTATION to show your work. Simplify your answers. e.g. if an answer is .08/.36, then .222 is the simplified answer.

a. Construct a tree diagram to display the data. Use probability notation. For example, write “P(C) = “ or “P(S|C) = “, etc. Place each probability and its numerical value on the correct branch of the tree in order to get full credit. There are 6 probabilities to place on the tree.

b. Calculate the probability that a server is contract managed and suffered a security incident.

c. Calculate the probability that a server is not contract managed and has suffered a security incident.

d. Calculate the probability of a security incident.

e. Given that a server suffered a security incident, calculate the probability that it is a contract managed server.

Answer 1