We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
98
3
avatar

We flip a fair coin 10 times. What is the probability that we get heads in exactly 8 of the 10 flips?

 May 28, 2019
 #1
avatar+102434 
+1

We have a binomial probability

 

C(10, 8)  * (.5)^8 * (.5)^2  = 45 / 1024  ≈  4.4%

 

 

cool cool cool

 May 28, 2019
 #2
avatar+191 
+1

We can also represent these using combinations.

We have to find the value of \(\binom{10}{8}.\)

A quicker way is to recognize Pascal's triangle, and this is the tenth row, and the sum is \(2^{10}=1024.\) Thus, the answer is, \(\frac{\binom{10}{8}}{1024}=\boxed{\frac{45}{1024}}.\) 

 May 28, 2019
 #3
avatar+102434 
0

THX, AZSUN  !!!!

 

 

cool cool cool

CPhill  May 28, 2019

8 Online Users