K Points: 0.5 of 2 In a survey of 3242 adults aged 57 through 85 years, it was found that 86.2% of them used at least one prescription medication. Complete parts (a) through a. How many of the 3242 subjects used at least one prescription medication? 2795 (Round to the nearest integer as needed.) b. Construct a 90% confidence interval estimate of the percentage of adults aged 57 through 85 years who use at least one prescription medication %