the mean and variance of a binomial distribution are 4 & 2 respectively.then the probability of 2 sucess is
option
a. 37/256
b. 219/256
c. 128/256
d. 28/256

• np=4
  np(1-p)=2
  p=1/2
  n=8
  nCr*(p^r)*q^(n-r)
  r=2
  q=1/2
  ans=28/256
• 10 years agoHelpfull: Yes(11) No(0)
• given,
  mean=4 and var=2
  but mean=np=4 and var=np(1-p)=2
  therefore, we get
  n=8, p=q=1/2
  p(x=2)=8C2*(1/2)^2*(1/2)^6
  p(x=2)=28/256
• 10 years agoHelpfull: Yes(8) No(0)