Find where a value is in a Range

I have a worksheet calculating a student's final grade based on inputs.
I would like to look up the calculated final grade from the table to determine the letter grade.

I.E., If the final grade is 60.83, look up that value from a table to give the letter grade of D-.

I have attached a sample workbook for reference. Any help is appreciated,

@6StringJazzer

Thank you, that works!