The dot plot below summarises the number of minutes 16 students spent on mathematics homework in one evening. The dots have been transcribed as follows (each dot represents one student):
15, 20, 20, 22, 25, 25, 25, 27, 30, 30, 30, 32, 35, 35, 37, 40
(i) From the dot plot write the least and the greatest number of minutes recorded.
(ii) Determine the range of the data.
(iii) A new student who spent 50 minutes on homework is added to the dot plot. Redraw the dot plot to include this observation and find the new range.