Hey guys I have a quick question on my hw, I have found everything needed except the "unusual scores". this is the direction given:

Determine which of the grades, if any, are "unusual" in the sense that their corresponding z-score is < -2.0 or > +2.0. A z-score is computed as:

I know what the x bar and the s is, but I am unsure of what the first x is pertaining to. Can anyone give me a few tips?

Thanks

``````public class hw05 {

public static void main( String [] args ) {

int [] grades = {98, 87, 78, 100, 99, 67, 69, 50,
88, 100, 88, 79, 60, 75, 93, 97,
40, 98, 88, 62, 58, 85, 92, 93,
59, 98, 94, 95, 87, 47, 69, 79,
89, 85, 68, 75};
int i;

}

public static void printArray(int [] a) {
for (int i = 0; i < a.length; i++ ) {
System.out.printf("%6d", a[i]);
if ((i + 1) % 5 == 0)
System.out.printf("\n");
}
}

public static int maxArray(int [] a) {
int max = Integer.MIN_VALUE;
for (int i = 0; i < a.length; i++)
if (a[i] > max)
max = a[i];
return max;
}

public static int minArray(int [] a) {
int min = Integer.MAX_VALUE;
for (int i = 0; i < a.length; i++)
if (a[i] < min)
min = a[i];
return min;
}

public static int sumGrades(int [] a) {
int sum = 0;
for (int i = 0; i < a.length; i++)
sum += a[i];
return sum;
}

public static double mean(int [] a) {
}

public static double sumSquares(int [] a) {
double ss = 0.0;
for (int i = 0; i < a.length; i++)
ss += (a[i] - mean(a)) * (a[i] - mean(a));
return ss;
}

public static double stdDev(int [] a) {
return Math.sqrt(sumSquares(a) / (a.length - 1));
}

}``````

i was looking for help with the code, i can use google too, thank you for the smart reply, that always helps when a beginner is asking a question

Do you understand the equation? The x you are looking for is the input value to find out what the z-score is. First you need to create a method which computes z-score. It requires you to have mean-x and s value before hand. Then, it takes a value which is called 'x', compute, and spit out the z-score. That's all it means. The code does not have the method and I believe you need to implement it.

``i was looking for help with the code, i can use google too, thank you for the smart reply, that always helps when a beginner is asking a question``

Jon was right on track. This is a Java forum, not a math forum.

Scores: 85, 90, 95

Z(85) = z = (85 - 90) / 3 = -1.67, within tolerance.

Scores: 85, 90, 95, 50

Z(50) = z = (50 - 80) / 4 = -7.5, outside tolerance...e.g out-liner

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