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A simple random sample with n = 55 provided a sample mean of 23.0 and a sample standard deviation of 4.1. a. Develop a 90% confidence interval for the population mean (to 1 decimal). ( . ) b. Develop a 95% confidence interval for the population mean (to 1 decimal). ( . ) c. Develop a 99% confidence interval for the population mean (to 1 decimal). ( . ) d. What happens to the margin of error and the confidence interval as the confidence level is increased? - Select your answer - c