Submit your r program) a discrete random variable y has sample space {1, 3, 7} and probability distribution {.2, .3, .5}. using r, you are to do the following: (a) find the expected value and population variance of y. (b) using 25,000 replications (artificial datasets) for sample sizes n = 10 and n = 1000, plot the distribution of the sample means. also plot the distribution of the sample variances. you must use ggplot to prepare your graphs.