There has been a great deal of discussion about global warming in recent years. In 2012, the Pew Research Center conducted a survey of 1,511 Americans to assess their opinion of global warming. The data show that 589 respondents of the 1,511 surveyed felt global warming is a very serious problem.
a. Estimate the proportion of all adult Americans who felt global warming is a very serious problem at the 95% confidence interval.
b. Estimate the proportion of all adult Americans who felt global warming is a very serious problem at the 99% confidence interval.
c. If you were going to write a report on this poll result, would you prefer to use the 99% or 95% confidence interval? Explain why.