SOLUTION: 1) The probability that a person is immune to a certain disease is 0.40. a)what is the probability that 4 people will have the disease in a sample of 12 people? b)find the mean n

Algebra ->  Probability-and-statistics -> SOLUTION: 1) The probability that a person is immune to a certain disease is 0.40. a)what is the probability that 4 people will have the disease in a sample of 12 people? b)find the mean n      Log On


   

Question 637665: 1) The probability that a person is immune to a certain disease is 0.40.
a)what is the probability that 4 people will have the disease in a sample of 12 people?
b)find the mean number of people who have immunity in a sample size of 12.
c) find the standard deviation for the sample size

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

1) The probability that a person is immune to a certain disease is 0.40.

Note: The probability of x successes in n trials is: 

P = nCx* p%5Ex%2Aq%5E%28n-x%29 where p and q are the probabilities of success and failure respectively.

 nCx = n%21%2F%28x%21%28n-x%29%21%29

 a)what is the probability that 4 people will have the disease in a sample of 12 people?  (.6)^4(.4)^8 

 b)find the mean number of people who have immunity in a sample size of 12. m = 12%2A.4

 c) find the standard deviation for the sample size  SD = sqrt%2812%2A.4%2A.6%29