1. College students were asked "How often do you wear a seatbelt when driving a car?" The results of the survey appear in the following table. Response Frequency Never 118 Rarely 249 Sometimes 345 Most of the time 716 Always 3093 a. Construct a probability model for seatbelt use by a driver.

b. Is it unusual for a college student to never wear a seatbelt when driving a car? Why or why not?

2. A theme park has five roller coasters: The Screamin' Eagle, The Boss, Mr. Freeze, Ninja, and Tony Hawk's Big Spin. Robert wants to ride two different roller coasters before leaving the park. He decides to select them by drawing names from a hat. a. Determine the sample space of the experiment.

b. What's the probability that he rides The Screamin' Eagle?

3. The following probability model shows the distribution for the number of rooms in U.S. housing units. Rooms Probability One .005 Two .011 Three .088 Four .183 Five .230 Six .204 Seven .123 Eight or more .156 a. What is the probability that a randomly selected housing unit has exactly six rooms?

b. What is the probability that a randomly selected housing unit has at least four rooms?

c. What is the probability that a randomly selected housing unit has at most three rooms?

4. Christmas lights are often designed with a series circuit. This means that when one light burns out the entire string of lights goes black. Suppose that the lights are designed so that the probability a bulb will last 2 years is .995. The success or failure of a bulb is independent of the success or failure of other bulbs. a. What is the probability that in a string of 100 lights all 100 will last 2 years?

b. What is the probability that at least one bulb will burn out in 2 years?