1. Assume eye colors in the U.S. are distributed as follows: 40% brown, 35% blue, 12% green, 7% gray, and 6% hazel. A statistics instructor collects eye color data from her students. Identify one factor that might make this sample biased.

Which ones of these are true and false?

2. Based on data from the Pew Internet Project, 74% of adult Internet users use social networking sites. If two adult Internet users are randomly selected, the probability they both use social networking sites is greater than 50%.

3. The United Van Lines Moving Company has a truck filled for deliveries to five different sites. If the order of the deliveries is randomly selected, the probability that the delivery is the shortest route is 1/120.

4. A coin is flipped twice. P(two heads) + P(two tails) = 1.