1..Suppose that a market research firm is hired to estimate the percent of adults living in a large city who have cell phones. Five hundred randomly selected adult residents in this city are surveyed to determine whether they have cell phones. Of the 500 people surveyed, 421 responded yes - they own cell phones. Using a 95% confidence level, compute a confidence interval estimate for the true proportion of adult residents of this city who have cell phones.

2...Suppose that a market research firm is hired to estimate the percent of adults living in a large city who have cell phones. Five hundred randomly selected adult residents in this city are surveyed to determine whether they have cell phones. Of the 500 people surveyed, 414 responded yes - they own cell phones. Using a 95% confidence level, construct a confidence interval estimate for the true proportion of adult residents of this city who have cell phones.

3. Based on the confidence interval you found in problem #2, does it appear that more than 80% of residents of this city have a cell phone? Why or why not.