Part 4) Uniform distribution {15 points) Suppose that your exams are graded using a uniform distribution between 50 and 100. Assume a continuous uniform distribution. a] What is the mean and standard deviation of this distribution? b] What is the probability of getting a score of at most 70? c) What is the probability of getting a score greater than 30 (use the lower.tail option)? d] What is the probability of getting a score between 90 and 100 (inclusive)