400
5, 6, 7, 6, 2, 8, 9, 8, 4, 6, 20, 4, 5, 4, 3, 6, 6. Find the range and the IQR for the above set of data. Explain which of these two measures of spread is more appropriate in this case. [4 minutes]
Range = 18, IQR = 3.5; IQR is more appropriate because it ignores the anomalous data value, 20.