Math Is Fun Forum
You are not logged in.
- Topics: Active | Unanswered
Pages: 1
#1 2010-04-17 17:31:27
- SmileAli
- Member
- Registered: 2010-04-02
- Posts: 10
Finding the Probability
Catherine would like to invite at least 5 of her friends to a party. Suppose each of her friends, if invited, independently agrees to come with probability 3/4. What is the probability that she will get 5 to agree to come if she invites 5 people?
The answer is (5 C 5) (0.75) ^5(0.25) ^0. So, where did the solution get 0.25???? Is there a formula for this?? Thanks
Offline
#2 2010-04-17 18:02:27
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Finding the Probability
Hi SmileAli;
That is the correct formula, and the answer is 243 / 1024 ≈ .237304
For k successes in n trials, p is the prob. of success and q is the prob of failure.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
Offline
#3 2010-04-18 06:44:38
- SmileAli
- Member
- Registered: 2010-04-02
- Posts: 10
Re: Finding the Probability
Thanks so much! I got it!!!
Offline
#4 2010-04-18 06:49:49
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Finding the Probability
Your welcome, glad to help.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
Offline
Pages: 1