In a dental survey conducted by a county dental health team, 500 adults were asked to give the reason for their last visit to a dentist. Of the 220 who had less than a high-school education, 44 said they went for preventative reasons. Of the remaining 280, who had a high-school education or better, 150 stated that they went for preventative reasons. Construct a 95 percent confidence interval for the difference between the two population proportions.