Use Excel (formulas) to answer questions

21. Which one ofthe following probability distrubutions accurately represent the random variable "the number of times heads come up in two tosses of a fair coin"? 22. Which one of the following probability distrubutions accurately represent the random variable "the numberof 6'5 that appear in a roll of two fair dice"? Below is a table showing the probability distribution for the random variable x X P(x) 20 0.064 30 0.288 40 0.432 50 0.216 23. Compute the variance of the random variable 24. Compute the standard deviation of the random variableIt is reported that 7% of the Super Star scratch-and-win lottery tickets are winners. If you scratch 250 tickets? 25. What is the expected number of winners? 26. What is the variance of the random variable "number of winners"? 27. What is the standard deviation of the random variable "number of winning tickets"?For a binomial distribution. 28. Find P(x=2), where n=8, p=0.7 29. Find P(3 5), where n=15, p=0.5 30. Find P(x > 2), where n=10, p=0.4