Four years after the survey described in Exercise C.48, in 2015, a different survey of 12,000 American adults found that 29.0% identified as Democrats and 26.0% identified as Republicans, with the rest identifying as independent or other. Answer the same questions about these survey results as in Exercise C.48: If we want 95% confidence, what is the margin of error in the estimate for the proportion of Democrats? For the proportion of Republicans? Do you feel comfortable concluding that in 2015 more American adults self-identified as Democrats than selfidentified as Republicans? Explain.

Data in Exercise C.48

A survey of 15,000 American adults in 2011 found that 35.3% identify as Democrats and 34.0% identify as Republicans, with the rest identifying as independent or other. If we want 95% confidence, what is the margin of error in the estimate for the proportion of Democrats? For the proportion of Republicans? Do you feel comfortable concluding that in 2011 more American adults self-identified as Democrats than self-identified as Republicans? Explain.