SOLUTION: 1. If you flip a fair coin five times in a row, what is the probability that you will have an outcome that has exactly four heads? 2. If you flip a fair coin five times in a row,

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Question 625534: 1. If you flip a fair coin five times in a row, what is the probability that you will have an outcome that has exactly four heads?
2. If you flip a fair coin five times in a row, what is the probability that you will have an outcome that has three or more heads?
3. If you flip a fair coin five times in a row, what is the probability that you will have an outcome that has two or fewer heads?

Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
Let x denote the number of heads.
1.
2. and 3. are pretty easy. By symmetry, P(x = 3) = P(x = 2) because the probability of obtaining a head and a tail is the same. Similarly, P(x = 4) = P(x = 1) and P(x = 5) = P(x = 0).
Therefore, without doing any calculations, we can say that P(x >= 3) and P(x <= 2) are both equal, and they are equal to 1/2.