D Question 3 16.67 pt The function f(x) = 2x is a probability density function on [0,a]. Find the value of a. 0 1 02 O 1/2 OO D Question 4 16.67 pts The function 2x2 - x is a probability density function on the interval [0,1]. True O False D Question 5 16.67 pts Find the mean of the random variable X with probability density function 3x2 - 2x + 1 on [0,1]. O T D Question 6 16.67 pts Find the variance of the random variable X with probability density function -32 X2 + 16 X + 32 on [-1, 3]. O