43. The number of customers at Winkies Donuts between 8:00a.m. and 9:00a.m. is believed
to follow a Poisson distribution with a mean of 2 customers per minute.
a. During a randomly selected one-minute interval during this time period, what is
the probability of 6 customers arriving to Winkies?
b. What is the probability that at least 2 minutes elapse between customer arrivals?
44. During lunchtime, customers arrive at Bob's Drugs according to a Poisson distribution
with = 4 per minute.
a. During a one minute interval, determine the following probabilities: (1) no
arrivals; (2) one arrival; (3) two arrivals; and, (4) three or more arrivals.
b. What is the probability of two arrivals in a two-minute period?
45. Telephone calls arrive at the Global Airline reservation office in Louisville according to a
Poisson distribution with a mean of 1.2 calls per minute.
a. What is the probability of receiving exactly one call during a one-minute
b. What is the probability of receiving at most 2 calls during a one-minute interval?
c. What is the probability of receiving at least two calls during a one-minute
d. What is the probability of receiving exactly 4 calls during a five-minute interval?
e. What is the probability that at most 2 minutes elapse between one call and the
46. Before dawn Josh hurriedly packed some clothes for a job-interview trip while his
roommate was still sleeping. He reached in his disorganized sock drawer where there
were five black socks and five navy blue socks, although they appeared to be the same
color in the dimly lighted room. Josh grabbed six socks, hoping that at least two, and
preferably four, of them were black to match the gray suit he had packed. With no time
to spare, he then raced to the airport to catch his plane.
a. What is the probability that Josh packed at least two black socks so that he will
be dressed appropriately the day of his interview?
b. What is the probability that Josh packed at least four black socks so that he will
be dressed appropriately the latter day of his trip as well?