Question 797724: you randomly selected 60 employees and ask them whether they would participate in such a program.
a) find the probability that exactly 35 will say yes.
b) find the probability that at least 40 will say yes
c) find the probability that fewer than 20 will say yes
d) based on the results from a-c, explain why you choose to perform the study
Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website!
The probability of  successes in  trials where  is the probability of success on any given trial is given by:
\ =\ {{n}\choose{k}}\left(p\right)^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 a):  ,  , and you didn't bother to share.
For your problem b): ,  , you didn't bother to share, and
\ =\ \sum_{i\,=\,k}^n\,{{n}\choose{i}}\left(p\right)^i\left(1\,-\,p\right)^{n\,-\,i}) .
 ranges from 40 to 60, 21 terms total.
For problem c): ,  , you didn't bother to share, and
\ =\ \sum_{i\,=\,0}^{k-1}\,{{n}\choose{i}}\left(p\right)^i\left(1\,-\,p\right)^{n\,-\,i})
ranges from 0 to 19, 20 terms total.
If you are either lazy, very smart, or both, Excel has a built-in function called BINOMDIST that calculates this stuff as fast as you can hit the enter key. Read the function help to learn how to use it. BTW, if you are on a Mac, the Numbers application has the exact same function that works the exact same way, at least from the user's point of view.
John
Egw to Beta kai to Sigma
My calculator said it, I believe it, that settles it
|
|
|
