Coin Tossing: Binomial Distribution Explained

[CaptainX]

Why tossing a coin three times is said to have binomial distribution? I'm little bit confused.

 

[fresh_42]

What is the probability to flip k heads in n trials?

 

[mathman]

Why tossing a coin three times is said to have binomial distribution? I'm little bit confused.

What is confusing?

 

[CaptainX]

What is the probability to flip k heads in n trials?

I think it's 1/2

 

[fresh_42]

I think it's 1/2

It doesn't matter if it's a fair coin or not. Say one coin flip has probability $p$ for heads. Now what is the probability of $k$ heads in $n$ flips? How any possibilities are there for $k$ out of $n$ and what is the combined probability?

 

[mathman]

Binomial: prob (k successes in n trials) $=\binom{n}{k}p^k(1-p)^{n-k}$ where $p$ is the probability of success on one trial. For fair coins $p=1/2$.

 

[fresh_42]

Binomial: prob (k successes in n trials) $=\binom{n}{k}p^k(1-p)^{n-k}$ where $p$ is the probability of success on one trial. For fair coins $p=1/2$.

... which is the answer to the question.

 

[CaptainX]

Binomial: prob (k successes in n trials) $=\binom{n}{k}p^k(1-p)^{n-k}$ where $p$ is the probability of success on one trial. For fair coins $p=1/2$.

Thank you very much!