In a poll of 2,003 adults within the United States for the Wall Street Journal, 57% of adults said that public education needs to be improved. Construct a 95% confidence interval for the proportion of all U. S. adults who hold this opinion.
a. Cannot be determined because more information is needed
b. approximately 0.548 to 0.592
c. approximately 0.50 to 0.591
d. approximately 0.57 to 0.61