SOLUTION: assume the random variable X has a binomial distribution with the given probability of obtaining a success find the following probability, given the sample size rounded your answe

Hi,

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



P = nCx*  where p and q are the probabilities of success and failure respectively. 

In this case p & q are = 1/2 or .5

nCx =   4C3 = 4    4C4 = 1

P(x≥3)= P(3) + P(4) 

P(3)=  4*(.5)^3(.5) = .25 

P(4)= .5^4 = .0625 

P(x≥3)= .25 + .0625 = .3125