According to the Pew Internet & American Life Project, 73%

of U.S. teens aged 12–17 used social networks. A random sample of 130 teenagers from this age group was selected.

a. Calculate the standard error of the proportion.

b. What is the probability that less than 75% of the teens from this sample used social networks?

c. What is the probability that between 70% and 80% of the teens from this sample used social networks?

d. What impact would changing the sample size to 200 teens have on the results of parts

a, b, and c?

AppendixLO1