A survey of 750 likely voters in Ohio was conducted by the Rasmussen Poll just prior to the general election (Rasmussen Reports website November 4, 2012). The state of the economy was thought to be an important determinant of how people would vote. Among other things, the survey found that 165 of the respondents rated the economy as good or excellent and 315 rated the economy as poor.

a. Develop a point estimate of the proportion of likely voters in Ohio who rated the economy as good or excellent.

b. Construct a 95% confidence interval for the proportion of likely voters in Ohio who rated the economy as good or excellent.

c. Construct a 95% confidence interval for the proportion of likely voters in Ohio who rated the economy as poor.

d. Which of the confidence intervals in parts (b) and (c) is wider? Why?