in 1964, two dolphins (buzz and doris) were trained to push one of two buttons in a pool in reaction to a light. if the light flashed, the dolphins pushed the button on the left to get a fish. if the light was constant, the dolphins needed to push the button on the right to get a fish. suppose the researchers are interested in whether buzz has truly learned the behavior to push a button correctly. they randomly make the light shine constant or flash 20 times, and record whether buzz pushes the correct button. define the random variable x as the number of times in which buzz pushes the correct button out of 20 attempts. if buzz has not learned the behavior, he would push buttons randomly and the probability that buzz pushes the correct button is 0.50.