A particular hair treatment program has caused hair growth in 70% of its users. A random sample of 20 users is obtained. Using the Binomial Probability Distribution, determine the following probabilities:
a) That exactly 15 experienced hair growth.
b) That less than 9 experienced hair growth.
c) That more than 12 experience hair growth.
d) That 15 or more experience hair growth.
e) That 7 or less experienced hair growth.