hi there! I just need some follow-up help on this stats problem. I only need help with option b, and any help is super appreciated!

In a survey of 3433 adults aged 57 through 85 years, it was found that 84.9% of them used at least one prescription medication. Complete parts (a) through (c) below. a. How many of the 3433 subjects used at least one prescription medication? 2,915 (Round to the nearest integer as needed.) b. Construct a 90% condence interval estimate of the percentage of adults aged 57 through 85 years who use at least one prescription medication. |:|%