You may need to use the appropriate appendix table or technology to answer this question. A sample survey of 62 discount brokers showed that the mean price charged for a trade of 100 shares at $50 per share was $33.88. The survey is conducted annually. With the historical data available, assume a known population standard deviation of $13. (a) Using the sample data, what is the margin of error in dollars associated with a 95% confidence interval? (Round your answer to the nearest cent.) $ (b) Develop a 95% confidence interval for the mean price in dollars charged by discount brokers for a trade of 100 shares at $50 per share. (Round your answers to the nearest cent.) to $ $