=+3.15. In a psychological experiment, the research question of interest is whether a rat "learned" its way through a maze during 65 trials. Suppose the time-ordered observa- tions on number of correct choices by the rat on each trail are as follows: 0, 1, 2, 1, 1, 2, 3, 2, 2, 2, 1, 1, 3, 2, 1, 2, 1, 2, 2, 1, 1, 2, 2, 1, 4, 3, 1, 2, 2, 1, 2, 2, 2, 2, 3, 2, 2, 3, 4, 3, 2, 3, 3, 2, 3, 3, 2, 3, 3, 2, 3, 4, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 4, 4