A psychology professor assigns letter grades on a test according to the following scheme. A: Top 6% of scores B: Scores below the top 6% and above the bottom 62% C: Scores below the top 38% and above the bottom 24% D: Scores below the top 76% and above the bottom 6% F: Bottom 6% of scores Scores on the test are normally distributed with a mean of 72.2 and a standard deviation of 8.6. Find the numerical limits for a D grade. Round your answers to the nearest whole number, if necessary.