SOLUTION: ​39% of a certain​ country's voters think that it is too easy to vote in their country. You randomly select 12 likely voters. Find the probability that the number of li

Algebra ->  Probability-and-statistics -> SOLUTION: ​39% of a certain​ country's voters think that it is too easy to vote in their country. You randomly select 12 likely voters. Find the probability that the number of li      Log On


   

Question 1120595: ​39% of a certain​ country's voters think that it is too easy to vote in their country. You randomly select 12 likely voters. Find the probability that the number of likely voters who think that it is too easy to vote is​
(a) exactly​ three, (b) at least​ four, (c) less than eight
(a) P(3)=____________
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
For 3, it is 12C3*0.39^3*0.61^9=0.1526
At least 4 is 1- prob (3), (2),1, and 0.
This is 1-0.2472=0.7528
8 voters has probability of 0.03667
9 probability is 0.0104
10 prob. is 0.0020
11 prob is 0.0002
12 prob is 0
The answer is 1-0.0493=0.9507,
same as binomcdf(12,0.39,7)