A door-to-door residential solar electrical system salesman is required to document four in-home visits each day. Suppose that she has a 25% chance of being invited into any given home(with each home representing and independent trial). (a) what is the probability that on a given day she makes her fourth in-home visit on the tenth home that she calls on (that is, on the tenth trial)? (b) what is the probability that she requires fewer than7 trials to make her fourth in-home visit? (c) Suppose she calls on 6 homes. What is the probability that she will meet or exceed her quota of 4 in-home visits?