Write a computer program that stores and tracks information
about high school students. The first piece of information is what
grade the student is in. Since this is for high school, the
available values are 9, 10, 11, and 12. We also want to track the
student’s GPA. Examples of GPAs are 2.2, 2.6, and 4.0. Finally, we
want to track the letter grade that the student got on his or her
final exam. These values are A, B, C,...