The final marks for the Wednesday class in Statistics 101 are ready to be posted. The class average is 72%, with a standard deviation of 9. The distribution of grades is approximately bell-shaped. a. What percentage of the grades are above 81? Percentage of grades b. What percentage of the grades are below 54? (Round the final answer to 1 decimal place.) Percentage of grades % c. What percentage of the grades are between 54 and 90? Percentage of grades % d. What percentage of the grades are between 54 and 81? (Round the final answer to 1 decimal place.) Percentage of grades % e. What percentage of the grades are between 54 and 99? (Round the final answer to 2 decimal places.) Percentage of grades % f. What percentage of the grades are less than 63 or more than 90? (Round the final answer to 1 decimal place.) Percentage of grades %