In a CBS News/New York Times nationwide poll done in 2009, the proportion of respondents who thought that it should be illegal to use a handheld cellular telephone while driving a car was .80 (80%). The poll's sample size was 829.
a. Find the value of the standard error of the sample proportion.
b. Find a 95% confidence interval estimate of the population proportion who think that it should be illegal to use a cellular telephone while driving.
c. Find a 98% confidence interval estimate of the population proportion who think that it should be illegal to use a cellular telephone while driving.
d. Which of the intervals calculated in parts (b) and (c) is wider-the interval with 95% confidence or the interval with 98% confidence?