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If a fair coin is tossed 9 times, what is the probability, rounded to the nearest thousandth, of getting at most 2 tails?

User Chikamichi
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2 Answers

13 votes
13 votes

Final answer:

The probability of getting at most 2 tails when a fair coin is tossed 9 times is approximately 0.090.

Step-by-step explanation:

To find the probability of getting at most 2 tails when a fair coin is tossed 9 times, we need to consider the possible outcomes and their probabilities.

There are a total of 2^9 = 512 possible outcomes when tossing a fair coin 9 times. To find the probability of getting at most 2 tails, we need to calculate the sum of the probabilities of getting 0, 1, or 2 tails.

The probability of getting 0 tails is (1/2)^9 = 1/512. The probability of getting 1 tail is 9/512, and the probability of getting 2 tails is 36/512. Adding these probabilities together gives us a probability of (1/512) + (9/512) + (36/512) = 46/512 = 0.08984

Therefore, the probability of getting at most 2 tails when a fair coin is tossed 9 times is approximately 0.090.

User Timothyjc
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7 votes
7 votes

Answer:

Below

Step-by-step explanation:

2^9 possibilities =512

9 possibles with only ONE tails (9 C 1)

36 possibles with TWO tails ( 9 C 2)

45 out of 512 45/512 = .088

User Aboodrak
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3.2k points