The table to the right shows the results of a survey in which 2585 adults from Country A, 1116 adults from Country B, and 1064 adults from Country C were asked if human activity contributes to global warming. Complete parts (a), (b), and (c).
Country A: 68%
Country B: 86%
Country C: 93%
(a) Construct a 90% confidence interval for the proportion of adults from Country A who say human activity contributes to global warming ( , )