below. 210 370 530 370 740 530 370 530 210 370 1140 210 A frequency distribution of this data set, based on a single-value grouping, is presented below with a third column showing the xf- values-the class midpoint (which here is the same as the class) times the class frequency. Salary(x) Frequency(f) Salary * Frequency(xf) 210 3 630 370 4 1480 530 3 1590 740 1 740 1140 1140 (i). Use the raw data to obtain the sample standard deviation of the ungrouped data. Round your answer to two decimal places. (6 points) Soln