A fair coin is tossed 8 times. What is the probability of exactly 4 heads?
Answer and explanation
Correct answer: B.
- Step 1: There are equally likely sequences with 4 heads out of .
- Step 2: Probability .
Answer
.
Why not the others: : the proportion of heads was used rather than the binomial probability. : the number of ways to arrange the heads was left out. : the denominator should be .
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