A weather forecaster states, “The chance of rain is 50% on Saturday and 50% again on Sunday. So there’s a 100% chance of rain sometime over the weekend.” If whether or not it rains on Saturday is independent of whether or not it rains on Sunday, find the actual probability of rain at least once during the weekend as follows:
a. Answer using methods from Chapter 5, such as by listing equally likely sample points or using the formula for the probability of a union of two events.
b. Answer using the binomial distribution.