A coin is flipped four times in a row. What is the probability that the result includes exactly one tails?

Question

tkhunny · Answer

Expand this...

$(p+q)^{4}$

...and ponder

anonymous · Answer

What is the p and the q?

tkhunny · Answer

Maybe it's a surprise?  Did you do it?

anonymous · Answer

I have no idea what exactly you're saying?

tkhunny · Answer

You're saying you've never multiplied a polynomial?

(p+q)(p+q)(p+q)(p+q)

tkhunny · Answer

Please read up on the Binomial Theorem and Binomial Distribution

$p^{4} + 4p^{3}q + 6p^{2}q^{2} + 4pq^{3} + q^{4}$

Now suppose p = p(heads) and q = 1-p = p(tails)

tkhunny · Answer

btw  The words "in a row" are meaningless in this problem statement.

anonymous · Answer

No it's probability. I just forgot how to figure it out. I've multiplied polynomials. I don't understand where you got p and q

tkhunny · Answer

What do you mean "no"?  Are polynomials somehow illegal in probability?

You are performing a Binomial Experiment.  The Probability of Heads is 1/2.  The Probability of Tails is 1/2.  You perform the experiment 4 times.

You might find it under "Binomial Distribution", n = 4, p = 1/2