A study was completed in California. In northern California, the study involved 1,000 patients; 74% of them experienced flulike symptoms during the month of December. The study had a margin of error of 3.2%. What does that mean for the study? The confidence interval is between 12.1% and 236.8%. The confidence interval is between 70.8% and 77.2%. The confidence interval is between 67.6% and 80.4%. The confidence interval is between 71% and 77%.