ACT PREP - Pretty much every problem ever

The video tutorial discusses the relationship between student absences and grades. The teacher explains how to use the line of best fit to predict grades based on the number of absences. A step-by-step example is provided to calculate the grade for a student with four absences, resulting in a B grade. The lesson concludes with advice on the importance of attending school.

What equation does the teacher use to predict the letter grade based on absences?

According to the teacher, what is the predicted letter grade for a student with four absences?