SOLUTION: If 20 people where selected at random, what is the probability that exactly 12 of those people have brown eyes?
Algebra.Com
Question 386535: If 20 people where selected at random, what is the probability that exactly 12 of those people have brown eyes?
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!
That depends. What is the probability that any one person selected at random has brown eyes? You would have to define the target population first as I'm sure P(brown) is different in the Northern Europe universe vs. the South America universe, for example. Be that as it may, let us assume that there is a number 
that represents the probability that any one person has brown eyes according to the population constraints that you establish. Note that 
.
The probability of 
successes in 
trials where is the probability of success on any given trial is given by:
\ =\ \left(n\cr k\right\)p^k\left(1\,-\,p\right)^{n\,-\,k})
Where )
is the number of combinations of things taken at a time and is calculated by !})
For your problem, 
, 
, and, for the time being, will just be left as a placeholder.
\ =\ \left(20\cr 12\right\)p^{12}\left(1\,-\,p\right)^{8})
Once you have determined the appropriate value of , fill it in and do the indicated arithmetic. If you are required to show your arithmetic work, you have quite a task ahead of you -- better start now. On the other hand, if you just need the answer and you have MS Excel or Apple Numbers available to you, open a blank spread sheet, select any cell you like, and type the following AFTER you have a valid value for .
)
Hit Enter and you will have your answer.
John
My calculator said it, I believe it, that settles it
RELATED QUESTIONS
If 60% of the population has brown eyes and we randomly select 12 people, what is the... (answered by ewatrrr)
in a certain town, 40% of the people have brown hair, 25% have brown eyes,and 15% have... (answered by oscargut)
If 20% of population have blue eyes, and 5 people are selected at random, what is the... (answered by sudhanshu_kmr)
PLEASE HELP!!!!
In the U.S, 40% of the population have brown eyes. If 14 people are... (answered by solver91311)
In the United States, 40% of the population have brown eyes.
If 17 people are randomly (answered by stanbon)
if 72% of all people have blue eyes and 6 people are selected at random, find the... (answered by stanbon)
It is known that 15% of all people have pets. If 15 people are selected at random, what... (answered by jjthomson83)
Of a class of 25 students, 18 have brown eyes. If 2 students are chosen at random, what... (answered by edjones,drk,solver91311)
In a class, 50% of the students have brown hair, 25% have black hair, 20% have blonde... (answered by opeodu)
