1. The following data set is a random sample of the length of call times in minutes for the customer service department at a small business. 7{11.1.11.5.11.9.13.1.14.6.15.2.15.8}meanofthisdataset.=13.3142857x=x/t b) Find the standard deviation of this data set. (You do not need to show all the steps, yet indicate the formula that was used.) Reotofn1(x1x)27122.32=3.72 c) What percentage of the data points are within two standard deviations of the mean