A particularly volatile common share has a 75% probability of moving up or down by the end of a day's trading. There is only a 25% chance of remaining at the same price. The change in price of the share on one trading day is independent of how it will perform on any other day. What is the probability of the share moving up or down in price, exactly six days out of seven? 86.7% 17.8% 42.8% 31.1%