(b) A sporting goods retailer wanted to evaluate the speeds of the 4 brands of motorbikes sell in their shop as part of an evaluation program. They took 5 of each brand and determined their maximum speeds. The results are presented in miles per hour in the table below: Brand A Brand B Brand C Brand D 43 37 41 43 46 38 45 45 44 38 42 46 43 39 43 46 45 37 42 44 At the 0.05 level of significance, is there evidence of a difference in the median speeds of the four motorbikes? (10 marks) [Total: 30 marks]