State one advantage and one disadvantage of using a box-and-whisker plot to show a set of data.
The marathon times, in minutes, for a group of 13 runners were recorded as follows: $180, 275, 235, 242, 311, 194, 246, 229, 238, 768, 332, 227, 228$. State which of the mean, mode or median is the most suitable measure of central tendency for these times. Explain why the other measures are less suitable.
A different group of 33 people also completed the same marathon and their times, in minutes, were: $190, 203, 215, 246, 249, 253, 255, 254, 258, 260, 261, 263, 267, 269, 274, 276, 280, 288, 283, 287, 294, 300, 307, 318, 327, 331, 336, 345, 351, 353, 360, 368, 375$. On the grid below, draw a box-and-whisker plot to show the times for these 33 people.
Find the interquartile range for these times.