probability of coin tosses

Hi, I have a probability problem that would like to seek help with. the question is simple: what is the probability of having 4 tails in 7 coin flips?
Much appreciated.

luzudizi said:

Hi, I have a probability problem that would like to seek help with. the question is simple: what is the probability of having 4 tails in 7 coin flips?

Click to expand...

If \(\displaystyle N>0\) and \(\displaystyle 0\le k\le N\) then flipping a coin \(\displaystyle N\) times, the probability of getting exactly \(\displaystyle k\) tails is \(\displaystyle \dbinom{N}{k}\cdot (0.5)^N\).