Marine scientists categorize signature whistles of bottlenose dolphins by typetype a, typeb, typec, etc. In one study of a sample of 185 whistles emitted from bottlenose dolphins incaptivity, 98 were categorized as type a whistles.

a. Estimate the true proportion of bottlenose dolphin signature whistles that are type a whistles. Use a 95% confidence interval.

b. Interpret the result