2. Exercise Stress Test. Campbell and Swinscow {2009] describe an experiment in which twenty patients, ten of normal weight and ten severely overweight underwent an exercise stress test. The patients had to lift a progressively increasing load for up to 12 minutes, but they were allowed to stop earlier if they could do no more. 011 two occasions the equipment malfunctioned before 12 minutes. The times (in minutes) achieved were: Normal weigh 2, 4, s, s, s**, 9, 10, 12*,12*,12* Overweight 1, 3, 4, 5, e, 7, 7**, a, 11, 12* Here, '\" means that the end of test was reached, and ** stands for equipment malfunction. Assume that the equipment does not fail and test does not have 12 minutes time limit, that is, all subjects are to stop only if they could do no more