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The following data represent the concentration of dissolved organic carbon (mg/L) collected from 20 samples of organic soil. Assume the population is normally distributed. 5.20 29.80 27.10 16.51 11.40 8.81 11.40 20.46 14.90 33.67 30.91 14.86 16.87 15.35 9.72 19.80 14.86 8.09 11.90 18.30 Find the sample mean. Round to the nearest hundredth as needed. Find the sample standard deviation. Round to the nearest hundredth as needed. Construct a 80% confidence interval for the population mean. Find the left end point for the confidence interval. Round to the nearest hundredth as needed. Construct a 80% confidence interval for the population mean. Find the right end point for the confidence interval. Round to the nearest hundredth as needed