Suppose that in the population of healthy children, VMA levels are Normally distributed with mean of 2.0 and a standard deviation of 0.3. Elevated VMA is defined as exceeding 2.3 mg. Compute each probability below using the pnorm function in R. Recall that for X~Normal(,o), pnorm(x, , o) returns Pr(X x). 1. What proportion of healthy children have elevated VMA levels? II. Suppose that you take a random sample of 9 healthy children. What is the probability that their mean VMA is greater than 2.3 mg? III. Suppose that you take a random sample of 25 healthy children. What is the probability that their mean VMA is greater than 2.3 mg?