Final answer:
An 84% score on a nursing exam is typically considered a B grade, but this may vary based on the specific grading policy of the institution.
Step-by-step explanation:
The letter grade corresponding to an 84% score on a nursing exam cannot be precisely defined without a specific grading scale. Different institutions have different grading scales, and some may use a curve. Typically, in most grading systems, especially those not adjusted by a curve, an 84% would translate to a B. This is based on a conventional scale where 90%-100% is an A, 80%-89% is a B, 70%-79% is a C, and so on.
In the context of Mr. Ahab's English class example, we see that 7.5% of students received a grade in the 90% to 100% range, which corresponds to an A. However, for a detailed and accurate assessment, it would be necessary to refer to the specific grading policy of the nursing program or institution.