A survey of stock market investors revealed 30% of individual investors have used a discount account. In a random sample of nine individual investors, what is the probability that:
a. Exactly 2 of the individual investors have used a discount broker?
b. None of the 9 individual investors have used the discount broker?
c. Two or three of the individual investors have used a discount broker?
d. What is the mean for this distribution?
e. What is the standard deviation for this distribution?