standard deviation in java

[noobplus]

hi
standard deviation formula is

I've x-values in yArray[]
and the code shows errors
and ive almost broken my head

	    double avgT=0;
	    double avgT2=0;
	    double[] SD =new double[TotalLineCount/4];//totallinecount is the number of lines in my input text file 
for(int j=0;j<TotalLineCount;j=j+4)
	    	  {
	    		
	    	     for(int k=j+0;k<j+4;k++)   //for every 4 values, Standard Deviation is found
	    	       {
	    	    	 System.out.println(avgT);
	    	    	 avgT=ReadPlatInstance.yArray[k]+avgT;  //this is E(X^2)
	    	    	 System.out.println(avgT);
	    		     avgT2=(ReadPlatInstance.yArray[k]*ReadPlatInstance.yArray[k])+avgT2;  //this is E(X)
	    		     System.out.println("\t k is "+k);	    		    
	    	        }
	    	     SD[j]=Math.sqrt(((avgT2/4)-((avgT/4)*(avgT/4)))/((4)*(4-1)));  //this part shows wrong answer. i've checked with "stdev" function in excel.

i would get relaxed for a second, if u tell me the error in the code

thanks
dhilip

[DarrylBurke]

i'd get relax a second if u temme the error in the code

thx

Please don't use non standard abbreviations in place of common words. This is a programming forum, not an SMS chat relay.

db