Suppose that a sample of 500 households in Phoenix was taken last May to determine whether the oldest child had given his/her mother a Mother's Day card. Of the 500 households, 421 responded yes. 15. Compute a 95% confidence interval for the true proportion of all Phoenix households whose oldest child gave his/her mother a Mother's Day card. A. (.76, .94) B. (.66, .98) C. (.81, .91) D. (.81, .874) 16. What was the margin of error in this case A. .09 B. .16 C. .05 D. .032 17. For a class project, a political science student at a large university wants to determine the percent of students that are registered voters. He surveys 500 students and finds that 300 are registered voters. Compute a 90% confidence interval for the true percent of students that are registered voters and interpret the confidence interval. A. (.504,.627) B. (.552, .630) C. (.564, .636) D. (.566, .638)