The following data represent the concentration of dissolved organic carbon (mg/L) collected from 20 samples of organic soil. Assume that the population is normally distributed. Complete parts (a) through (c) on the right. 11.40 29180 27.10 16.51 17.50 8.81 15.72 20.46 14.90 33.67 30.91 14.86 16.87 15.35 9.72 19.80 14.86 8.09 5.20 18.30 (a) Find the sample mean. The sample mean is (Round to two decimal places as needed.) (b) Find the sample standard deviation. The sample standard deviation is (Round to two decimal places as needed.) (c) Construct a 98% condence interval for the population mean u. The 98% condence interval for the population mean p is ( , ,). (Round to two decimal places as needed.)