A philosophy professor assigns letter grades on a test according to the following scheme.

A: Top12%of scores

B: Scores below the top12% and above the bottom63%

C: Scores below the top37% and above the bottom22%

D: Scores below the top78% and above the bottom7%

F: Bottom7% of scores

Scores on the test are normally distributed with a mean of72 and a standard deviation of8.1. Find the numerical limits for a B grade. Round your answers to the nearest whole number, if necessary.