Question 1192329
.
When throwing a coin the chance of it being heads is 0.63. 
If a person gets heads - they step one step to the right, if tails - one step to the left. 
(a) What is the probability of being back at the starting point (before making any steps) after 8 throws? 
(b) What is the probability of being no more than 4 steps away from the starting point after 8 throws?
~~~~~~~~~~~~~~~~~~~


<pre>
(a)  Event (a) is an event having four heads and four tails among the eight throwing the coin.


     The experiment throwing a coin is a binomial distribution, so the probability of this event is

          P = {{{C[8]^4*0.63^4*(1-0.63)^4}}} = {{{70*0.63^4*0.37^4}}} = 0.206665   (rounded).    <U>ANSWER</U>
</pre>

Solved.


----------------


See the lesson

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/Probability-and-statistics/Challenging-problems-on-Binomial-distribution-probability.lesson>Challenging problems on Binomial distribution probability</A> 

at this forum.