Understanding Coin Flip Probabilities: A Guide to Coin Tossing

A fair coin is continually flipped. What is the probability that the first four flips are

(a) H, H, H, H?

(b) T, H, H, H?

(c) What is the probability that the pattern T, H, H, H occurs before the pattern

H, H, H, H? 

Coin flipping is a popular activity that many people are familiar with. Whether it's for making a decision or for fun, we often think about the probabilities involved in coin flipping. In this post, we'll be exploring the probabilities of different sequences of heads (H) and tails (T) in a fair coin flip.

First, let's look at the probability of getting four heads (H, H, H, H) in a row. Since each flip of a fair coin is an independent event, the probability of getting heads on each flip is 0.5. The probability of getting four heads in a row is calculated by multiplying the probabilities of each flip:

P(H, H, H, H) = 0.5 * 0.5 * 0.5 * 0.5 = 0.0625 or 1/16

Next, let's consider the probability of getting the pattern T, H, H, H. The probability of getting tails on the first flip is 0.5, and the probability of getting heads on the next three flips is 0.5 * 0.5 * 0.5 = 0.125. The probability of getting the pattern T, H, H, H is the product of these probabilities:

P(T, H, H, H) = 0.5 * 0.125 = 0.0625 or 1/16

Finally, let's consider the probability that the pattern T, H, H, H occurs before the pattern H, H, H, H. This is a little more complex to calculate, as we need to consider the different possible sequences of heads and tails. However, we can use a simple method to estimate this probability.

Since the probability of getting T, H, H, H or H, H, H, H is the same (0.0625 or 1/16), the probability of getting either pattern is 2 * 0.0625 = 0.125 or 1/8. The probability that T, H, H, H occurs before H, H, H, H is equal to half of this value, since there are two possible sequences.

P(T, H, H, H occurs before H, H, H, H) = 0.125 / 2 = 0.0625 or 1/16

Understanding the probabilities of different sequences of heads and tails in a coin flip can help us make better decisions and predictions. By using simple methods, we can estimate the probabilities of getting specific sequences, such as H, H, H, H, T, H, H, H, or the order in which these sequences occur.