A physiology professor assigns letter grades on a test according to the following scheme: A: top 14% of scores B: Scores below the top 14% and above the bottom 65% C: scores below the top 35% and above the bottom 23% D: scores below the top 77% and above the bottom 5% F: bottom 5% of scores Scores on the test are normally distributed with a mean of 66.9 and a standard deviation of 7.9. Find the numerical limits for a B grade. Round your answers to the nearest whole number