Independent = neither Democrat nor Republican
P(Independent) = 0.11
n = 35 people surveyed
a.) Complement Rule: P(not Independent) = 1 - P(Independent) = 1 - 0.11 = 0.89
The probability that none of the people are Independent is 0.89.
b.) Use the binomial probability formula to find the probability that fewer than 5 people are Independent.
P(X = x) = C(35, x) * (0.11)x * (0.89)35 - x , where x is the number of people selected who are Independent.
P(X < 5) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) = 0.6601
The probability that fewer than 5 people who are Independent is about 0.6601.
c.) Complement Rule: P(X > 2) = 1 - P(X ≤ 2) = 1 - [P(X = 0) + P(X = 1) + P(X = 2)] = 1 - 0.244 = 0.756
The probability that more than 2 people who are Independent is about 0.756.