Derive a class named Student from the class Person (implemented in programming assignment#1). A Student object has a name and an identification number (both inherited from the class Person), two test scores (int), the average score (double) and a letter grade (char). Write the definitions for the constructors, a number of appropriate accessor and mutator methods as well as an equals () and a toString) method for the Student class. Write a Java program to read in the name, the id and the two test scores for 5 students from the keyboard and then compute the letter grade for each student according to the following scale: average 90 is an A 80