A X is a continuous random variable with probability density function 4/ (x+ 1) ', x>0 f ( x) = 0, x50. Which of the following is the cumulative distribution function of X? O F(x) = 20/ (x+1), x>0 O F(x) =1-1/(x+1)4, x>0 O F(x) = -1/(x+1)4 x>0 B A continuous random variable X has cdf (1+x) F(x) = O. elsewhere. Find P(1.0 2. Which of the following is the probability density function of X? O 2(x+ 1) -1 2 O -1