import java.util.Scanner; /** * Students in a course take four exams and earn a letter grade (A, A-, B+, B, * B-, C+, C, C-, D+, D, D-, or F) for each of them. The course grade is * determined by dropping the lowest grade and averaging the three remaining * grades. To average grades, first convert them to number grades, using the * usual scheme A = 4.0, A- = 3.7, B+ = 3.3, . . ., D- = 0.7, F = 0. Then * compute their average and convert it back to the closest letter grade. For * example, an average of 3.51 would be an A-. * * Your task is to read inputs of * the form: letterGrade1 letterGrade2 letterGrade3 letterGrade4 * For example, A- B+ C A * * For each input line, your output should be letterGrade where the * letter grade is the grade earned in the course, as just described. * For example, A * * The end of inputs will be indicated by a letterGrade1 field of -. * * @author smitra * */ public class grades { /** * The program starts executing in the main method. It keeps calling processALine * method until it returns false. * * @param args */ public static void main(String[] args) { Scanner in = new Scanner(System.in); System.out.print("Please enter four letter grades: "); double letterGrade1; double letterGrade2; double letterGrade3; double letterGrade4; letterGrade1 = in.nextDouble(); letterGrade2 = in.nextDouble(); letterGrade3 = in.nextDouble(); letterGrade4 = in.nextDouble(); } /** * Processes one line of input. * @return true if the sentinel (the - character) was not encountered */ static boolean processALine(Scanner in) { if (letterGrade1 != "-") return true; return false; // this line is just a placeholder } /** * Returns the smallest of four numbers. * * @param a a number * @param b a number * @param c a number * @param d a number * @return the smallest of a, b, c, and d */ public static double min(double a, double b, double c, double d) { // TODO: write code for this method return 0; // this line is just a placeholder } /** * Converts a number to the nearest letter grade using the * usual scheme A = 4.0, A- = 3.7, B+ = 3.3, . . ., D- = 0.7, F = 0. * * For example, if x is the number grade, then we have: * 2.5 ² x < 2.85: B- * 2.85 ² x < 3.15: B * 3.15 ² x < 3.5: B+ * * Similarly, for other numbers. * * @param x a number between 0 and 4 * @return the nearest letter grade */ public static String numberToGrade(double x) { if (n == "A") return "4.0"; if (n == "A-") return "3.7"; if (n == "B+") return "3.3"; if (n == "B") return "3.1"; if (n == "B-") return "2.8"; if (n == "C+") return "2.4 "; if (n == "C") return "2.0 "; if (n == "C-") return "1.7 "; if (n == "D+") return "1.3 "; if (n == "D") return "1.0 "; if (n == "D-") return "0.7"; if (n == "F") return "0.0"; return ""; // this line is just a placeholder } /** * Converts a letter grade to a number using the * usual scheme A = 4.0, A- = 3.7, B+ = 3.3, . . ., D- = 0.7, F = 0. * * @param grade a letter grade (A+, A, A-, . . ., D-, F) * @return the equivalent number grade */ public static double gradeToNumber(String grade) { if (n == "A") return "4.0"; return 0; // this line is just a placeholder } } // end of class Grades

Can someone help me out. Am i on the right track when it comes to the main method? Also going into the boolean method i'm not sure what i'm asked to do..any help would be appreciated