Using Probabilities for Unusual Events

a. Find the probability of getting exactly one car that fails among six cars tested.

b. Find the probability of getting one or fewer cars that fail among six cars tested.

c. Which probability is relevant for determining whether one is an unusually low number of cars that fail among six cars tested: the result from part

(a) or part (b)?

d. Is one an unusually low number of cars that fail among six cars tested? Why or why not?