Create a Java application (with generated comments) to simulate a GradeBook. A teacher has five students who have taken four exams. The teacher uses the following grading scale to assign a letter grade to a student, based on the average of his or her four exam scores:

Average	Letter Grade
90 100	A
80 89	B
70 79	C
60 60	D
0 59	F

Write logic to create a String array to hold student names, a character array to hold student letter grades, and a two-dimensional array to hold each of the five students test scores for each of the four exams completed during the semester.

Use nested for loop logic to fill the names and test scores arrays. Do not accept test scores less than zero or greater than 100. Make sure you test both ends of the range!

Use another nested for loop to compute the average test score for each student and then assign the corresponding letter the letter grade array. Make sure you test each letter grade value!

Use while loop logic to display each students name and letter grade in tabular fashion.