An experiment consists of tossing a coin two times and observing the sequence ofheads and tails. Each ofthe four outcomes has the same probability ofoccurring. [a] What is the probability ofthe event "at least one head"? [b] What is the probability that "HH" is the outcome? [3] What is the probability ofthe event "at least one head"? F" Pr(at least one head) = E (Type an integer or a simplified fraction.) [b] What is the probability hat "HH" is the Pr(HH) =I (Type an integer or a simplified fraction.)