It is estimated that 9% of those taking the quantitative methods portion of the certified public accountant (CPA) examination fail that section. Eighty students are taking the examination this Saturday. a-1. How many would you expect to fail? (Round the final answer to 2 decimal places.) Number of students 7.20 0 a-2. What is the standard deviation? (Round the final answer to 2 decimal places.) Standard deviation 0 b. What is the probability that exactly four students will fail? (Round the final answer to 4 decimal places.) Probability 0.0800 0 c. What is the probability at least four students will fail? (Round the final answer to 4 decimal places.) Probability