Sometimes police use a lie detector test to help determine whether a suspect is telling the truth. A lie detector test isn’t foolproof sometimes it suggests that a person is lying when he or she is actually telling the truth (a “false positive”). Other times, the test says that the suspect is being truthful when he or she is actually lying (a “false negative”). For one brand of lie detector, the probability of a false positive is 0.08.

a. Explain what this probability means.

b. Which is a more serious error in this case: a false positive or a false negative? Justify your answer.