write a program that initializes an array with 30 integers then calculates the m

Question

write a program that initializes an array with 30 integers then calculates the mean value and standard deviation (is calculated as sqrt(((value i - mean)^2)/n). the program then print the values on three separate lines , 10 integers per line (separated by few blanks), and prints the mean and the standard deviation. for testing please use the values 1.....30.
!!!!!!!!!!!!!!!!!!!!!!!!QUESTION TO BE ANSWERED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
REDO the above program using a different method:

**/ method that initializes the array
* @ returns an array of doubles
*/
Public static int[] initialize ()

Explanation / Answer

public static void initialize(int[] data)
{
for(int i = 0; i < data.length; i++)
data[i] = i+1;
}

public static double mean(int[] data)
{
int sum = 0;

for(int i : data)
sum += i;
return (double)sum/data.length;
}

public static double standardDeviation(int[] data)
{
double variance = 0.0;
double mean = mean(data);

for(int i : data)
variance += (i-mean)*(i-mean);
variance = variance/data.length;
return Math.sqrt(variance);
}

public static void main(String[] args)
{
int[] data = new int[30];
initialize(data);
// print data
for(int i = 0; i < 30; i++)
{
if(i%10 == 0)
System.out.println();
System.out.print(data[i]+" ");
}
// output mean and standard deviation
System.out.println();
System.out.println("Mean: "+mean(data));
System.out.println("Standard deviation: "+standardDeviation(data));
}

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