Obtaining a driver’s license at the earliest eligible age has been a teenage ritual that appears to be fading. A study performed by the University of Michigan Transportation Research Institute recently found that 30% U. S. teenagers between the ages of 17 to 19 did not possess a driver’s license. A random sample of 140 17 to 19 year old teenagers was selected.

a. What is the probability that 45 or fewer teenagers of this sample had not obtained a driver’s license?

b. What is the probability that 50 or more teenagers of this sample had not obtained a driver’s license?

c. What is the probability that between 35 and 40 teenagers had not obtained a driver’s license?

d. Suppose that 28 teenagers from this sample had not obtained a driver’s license? Does this result support the findings reported by the University of Michigan Transportation Research Institute?