Suppose y is the number of in volume v and assume that y follows the poisson distribution with mean λv. a. if a point is randomly selected within the volume v find the pdf of its distance r from the nearest pollution particle. note the volume of a sphere with radius r is 4 3 πr3 . b. refer to question (a). let u = r3 . show that u follows exponential distribution. what is the mean and variance of u?