33. Same-Sex Marriage The results of a 2017 Gallup poll concerning views on same-sex marriage showed that of n51011 adults, 64% thought that same-sex marriage should be valid, 34% thought it should not be valid, and 2% had no opinion.9 The poll reported a margin of error of plus or minus 4%.

a. Construct a 90% confidence interval for the proportion of adults who think same-sex marriage should be valid.

b. Construct a 90% confidence interval for the proportion of adults who do not think same-sex marriage should be valid.

c. How did the researchers calculate the margin of error for this survey? Confirm that their margin of error is correct.