binomial experiment: Assume experiment is repeated N times.

[serenity26]

okay this is my question.

Assume that an experiment was repeated N times. find the probability of X sucess gien the probability p of sucess on a given trial with N=12 , X=5 , P= .3.


I use the formula P(x)=n!/(n-x)!x! and then times that by P to the x power times Q to the n-x power so i got P(x)=479001600/7!5! = 479001600/604800=792 then the second part i did 0.3 to the 7th power = 0.0002187 and Q to the n-x power= .7 to the 7th power =0.0823543. then times them all together 792 (0.0823543 x 0.0002187) =0.0143 is this right or did i do something wrong.

 

[pka]

Re: binomial experiment

okay this is my question. Assume that an experiment was repeated N times. find the probability of X sucess gien the probability p of sucess on a given trial with N=12 , X=5 , P= .3.

\(\displaystyle \L\left( {\begin{array}{c}
{12} \\
5 \\
\end{array}} \right)\left( {.3} \right)^5 \left( {.7} \right)^7 .\)

 

[serenity26]

so goes that mean i applied the wrong formula or does the second x don't count (n-x)!x!

 

[pka]

so goes that mean i applied the wrong formula or does the second x don't count (n-x)!x!

Sorry to say but I do not understand what you could possibly mean!
Where is there any 'second x"?
Did you do the calculation I suggested?