Suppose that the rigidity of employment index is determined as an average measure of the difficulty of hiring, the difficulty of firing, and a rigidity of working hours. This index ranges from 0 to 100 where higher numbers represent higher labour market rigidity. Using the rigidity of employment index values for sampled developed countries: 28.42,48,45.55,60.50.49 the sample standard deviation is found as ()a) 3.372 ()b) 3.993 O c) 3.427 d) None of the answers are correct e) 2470