Y₁, Y2, ..., Yn are i.i.d. Bernoulli random variables with p = 0.7. Let Y denote the sample average. 20) What is the E(Y) 21) What is the var(Y) 22) Let n=50. Using the central limit theorem, right out the approximate distribution of Y~ 23) Using the approximate distribution from above and a z score table, what is the Pr(Y ≤ 0.66) when n = 50. 24) Now lets take a larger sample, so now n=100. What is the probability that the Sample average of Y is greater than .75