What is the Probability of Getting More Heads than Tails in 4 Coin Tosses?

[tae3001]

A coin is tossed 4 times. What is the probability of getting more heads than tails?

 

[juvenal]

Use the binomial distribution.

 

[JamesU]

I'm guessing about 25%

 

[Zaare]

Juvenal's suggestion is good, but I thought I'd give you an alternate way of solving the problem. What is the probability of a certain combination och heads and tails? For example: first throw you ger tail, the three following throws heads come up. Then, think about in how many such combinations you would get more heads than tails.

 

[tae3001]

Use the binomial distribution.

is there.. a formula for it..
if its tossed 4 times.. and there are 2 sides..
wouldn't it be 4 choose 2?
if there are more H that t would it be HHH and T...
i hate probability questions..

 

[juvenal]

The formula for the binomial distribution is standard, and you don't have to think.

http://mathworld.wolfram.com/BinomialDistribution.html

 

[Zaare]

Every time you throw there is 50% chance of T and 50% of H.
So, if you throw once you have (P(x)=probability that x happens):
1. P(H)=1/2
2. P(T)=1/2.
If you thow twice:
1. P(H,H)=(1/2)*(1/2)=1/4
2. P(H,T)=(1/2)*(1/2)=1/4
3. P(T,H)=(1/2)*(1/2)=1/4
4. P(T,T)=(1/2)*(1/2)=1/4
If you throw four times there is 1/16 chance you'll get one of the 16 combination:
1. HHHH, 2. HHHT, 3. HHTH,... etc.
These three examples are all more Heads than Tails, how many more such combinations are there? If you can answer that, you're done.

 

[tae3001]

I get it.. thanx.. u guys helped me graduate..(LOL).. awesome..