A Pew Internet & American Life Project study based on 1100 random telephone calls with children ages 12 to 17 and their parents was conducted from October 26 to November 28, 2004.

The survey found that 13% of American teens do not use the Internet. The findings have a margin of sampling error of plus or minus 3 percentage points.

Source: http://www.usatoday.com/news/bythenumbers/

2005-03-18-teen-net-use_x.htm You wish to conduct a study to estimate the percentage of children 12 to 17 years old who do not use the Internet and live in your state. Assume the population proportion is 13% as reported by Pew Internet & American Life Project. What sample size must you use if you want your estimate to be within:

a. 0.03 with 90% confidence

b. 0.06 with 95% confidence

c. 0.09 with 99% confidence