Answer:
0.6708 or 67.08%
Step-by-step explanation:
Helen can only make both free throws if she makes the first. The probability that she makes the first free throw is P(C) = 0.78, now given that she has already made the first one, the probability that she makes the second is P(D|C) = 0.86. Therefore, the probability of Helen making both free throws is:
There is a 0.6708 probability that Helen makes both free throws.