找不到符号

import java.io.*;
public class Average{
private KeyboardReader reader=new KeyboardReader();
private double promptAndRead(){
reader.prompt("Input a grade (e.g.,85.3)"+"or 9999 to indicate the end of the list>>");
double grade=reader.getKeyboardDouble();
System.out.println("You input[size=large][/size]"+grade+"\n");
return grade;
}
public double inputAverageGrades(){
double runningTotal=0;
int count=0;
double grade=promptAndRead();
while(grade!=9999){
runningTotal+=grade;
count++;
grade=promptAndRead();
}
if(count>0)
return runningTotal;
else return 0;
}
public static void main(String args[]){
System.out.println("this program calculates average grade.");
Average avg=new Average();
double average=avg.inputAndAverageGrades();
if(average==0)
System.out.println("you didn't enter any grades");
else
System.out.println("you average is"+average);
}
}
编译时出现错误
符号： 方法 inputAndAverageGrades()
位置： 类 Average
double average=avg.inputAndAverageGrades()
                  ^                  ^