According to the Anxiety and Depression Association of America (ADAA), approximately 4% of all adults have attention-deficit/hyperactive disorder (ADHD).30 An experiment consists of selecting adults at random and asking them if they have ADHD.
a. What is the probability that the fifth adult selected will be the first with ADHD?
b. What is the probability that at least eight adults will be selected before identifying a person with ADHD?
c. What is the mean number of adults that must be selected before identifying a person with ADHD?
d. Suppose the 35th adult is the first with ADHD. Is there any evidence to suggest the ADAA claim is false? Justify your answer.
According to recent FBI statistics, the mean number of bank robberies per day in the Southern Region of the United States is 4.32.31 Suppose a day is selected at random.
a. What is the probability of exactly two bank robberies in the Southern Region? Write a Solution Trail for this problem.
b. What is the probability that there will be more than eight bank robberies on that day in the Southern Region?
c. Suppose two days are selected at random. What is the probability that there will be no robberies in the Southern Region on both days?
According to a recent study, 30% of all computers in the United States are infected with some form of malware.32 Suppose a computer repair specialist carefully checks every machine left at his store.
a. What is the probability that the second computer examined will be the first to have malware? Write a Solution Trail for this problem.
b. What is the probability that the tenth machine examined will be the first to have malware?
c. What is the mean number of computers examined before one will be infected with malware?
d. What is the probability that at least five computers will be examined before one will have malware?