In a survey of 1000 Americans, 850 said that they own a cell phone. Assume that the survey was properly conducted and that the 1000 people surveyed represent an unbiased sample of the entire population. Compute a 99.7% confidence interval (expressed using percents) for this survey.
◦ 84.8% to 85.2%
◦ 82.8% to 87.2%
◦ 84.08% to 85.02%
◦ 83.9% to 86.1%
◦ 81.7% to 88.3%