(c) if you wanted to distinguish the top 20% of ARI scores from the bottom 80%, what would be the score that could be used as the cut-off? Show your work and write your answer in the box. (2) If, in a population, variable X is normally distributed with mean 70 and standard deviation 4, find the following probabilities. (a) P(x) 2 70.5 when a random sample of 200 is taken from the population. (b) P(x)