Elysian Shadows

Posted: **Wed Dec 02, 2009 12:52 pm**

Hi, i need help with this code just a bit. I am wondering what am i doing wrong with my "average" I don't expect you guys to just give me my answer but if you can point me in the right direction i would love you all!! underneath the code is what i am SUPPOSED to have and only the average section is wrong.

Code: Select all

public class GradesV2
{
    public static void main(String[ ] args)
    {
       //Local variables
       int totalPoints = 0;
       int numTests = 0;
       int testGrade = 0;
       double average = 0.0;
       
       
       testGrade = 97;
       totalPoints += testGrade;
       numTests ++;
       average = totalPoints / testGrade;
       System.out.print("n = " + numTests + " New test grade: " + testGrade + " total points: " + totalPoints + " average: " + average);
    
    
       testGrade = 79;
       totalPoints += testGrade;
       numTests++;
       average = totalPoints / testGrade;
       System.out.println();
       System.out.print("n = " + numTests + " New test grade: " + testGrade + " total points: " + totalPoints + " average: " + average);
    
       
       testGrade = 83;
       totalPoints += testGrade;
       numTests++;
       average = totalPoints / testGrade;
       System.out.println();
       System.out.print("n = " + numTests + " New test grade: " + testGrade + " total points: " + totalPoints + " average: " + average);
     
       
       testGrade = 88;
       totalPoints += testGrade;
       numTests++;
       average = totalPoints / testGrade;
       System.out.println();
       System.out.print("n = " + numTests + " New test grade: " + testGrade + " total points: " + totalPoints + " average: " + average);
    
    }
}

This is what my result should be but it's not.

n = 1 New test grade: 97 total points: 97 average 97.0
n = 2 New test grade: 79 total points: 176 average 88.0
n = 3 New test grade: 83 total points: 259 average 86.3333333
n = 4 New test grade: 88 total points: 347 average 86.75

Posted: **Wed Dec 02, 2009 1:07 pm**

you might wanna look at how averages are calculated. im assuming you just want the arithmetic mean.
but i looks something like this

(Î£ x)/n

Posted: **Thu Dec 03, 2009 6:32 pm**

This looked like a nice little challenge lol.
You want to make something like this:

Code: Select all

public class GradesV2
{
    public static void main(String[ ] args)
    {
       //Local variables
       int totalPoints = 0;
       int numTests = 0;
       int testGrade = 0;
       double average = 0.0;
       
       
       testGrade = 97;
       totalPoints += testGrade;
       numTests ++;
       average = (double)totalPoints/numTests;
       System.out.print("n = " + numTests + " New test grade: " + testGrade + " total points: " + totalPoints + " average: " + average);
    
    
       testGrade = 79;
       totalPoints += testGrade;
       numTests++;
       average = (double)totalPoints/numTests;
       System.out.println();
       System.out.print("n = " + numTests + " New test grade: " + testGrade + " total points: " + totalPoints + " average: " + average);
    
       
       testGrade = 83;
       totalPoints += testGrade;
       numTests++;
       average = (double)totalPoints/numTests;
       System.out.println();
       System.out.print("n = " + numTests + " New test grade: " + testGrade + " total points: " + totalPoints + " average: " + average);
     
       
       testGrade = 88;
       totalPoints += testGrade;
       numTests++;
       average = (double)totalPoints/numTests;
       System.out.println();
       System.out.print("n = " + numTests + " New test grade: " + testGrade + " total points: " + totalPoints + " average: " + average);
    
    }
}

Your errors:
1.) average should always be the total points divided by the number of tests. That's just how you get averages.
2.) you need to use a cast (for converting int to double) on one of the int variables so that you produce real doubles (instead of just .0 on the end).

Elysian Shadows

Java help.

Java help.

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