The cumulative distribution function of a continuous random variable is given as follows: 0 0 ( ) 0 5 5 1 5 X if x x F x if x x a. Determine and name the density function of .  b. Use both and ( ) X F x to find P(X 3) .  c. Find the variance of .  d. Use the method to find the probability density function of . e. Find the variance of .