D Question 7 10 pts Let f(x) = k(3x - x2) if 0 > 3. For the following questions, if your answer is not a whole number, enter it as a fraction a/b in lowest terms. A. For what value of k is f a probability density function? k = B. For that value of k, find P(X > 1). P(X > 1) = C. Find the mean. U =D Question 8 10 pts 1 The time between infection and the display of symptoms for streptococcusore throat is a random variable whose probability density function can be approximated by f (t) = 15676 -the 0.05# if 0