The following data were produced in a test of an intruder detection security system at a radiological medicine laboratory under conditions of high or low electromagnetic interference. Determine all of the conditional and marginal probabilities relevant to this problem, and then, if the probability of an actual intruder is $0\mathrm{.}02,$ calculate what is the chance that an intruder alert indicates an actual intruder under two separate conditions of high or low interference.