Population Standard Deviation - java

[cemma]

Hello!

So i am a new programmer and i really need some help. I am trying to find the Population Standard Deviation of 7 numbers which the user inputs.

Please see below my

        double dayOne, dayTwo, dayThree, dayFour, dayFive, daySix, daySeven, avgRain = 0, stanDeviation = 0, dayOneSq = 0, dayTwoSq, dayThreeSq, dayFourSq, dayFiveSq, daySixSq, daySevenSq, avgRainSq; 
        
        
        //Get rainfall information from users.
        
        System.out.println("Enter rainfall measurement for Day 1 (in mm): ");
        dayOne = reader.nextDouble();
        
        System.out.println("Enter rainfall measurement for Day 2 (in mm): ");
        dayTwo = reader.nextDouble();

Etc, Etc.

     //find average
        
avgRain = (dayOne + dayTwo + dayThree + dayFour + dayFive + daySix + daySeven)/7;
	
     // calculate population deviation
        
        dayOneSq = (dayOne - avgRain);
        	  Math.pow(2,dayOneSq);
	
        dayTwoSq = (dayTwo - avgRain);
        	Math.pow(2,dayTwoSq);
        
        etc..etc...
        
        //find standard deviation
        
        avgRainSq = (dayOneSq + dayTwoSq + dayThreeSq + dayFourSq + dayFiveSq
        				+ daySevenSq)/7;
       
        stanDeviation = (Math.sqrt(avgRainSq));


System.out.printf (", Standard Deviation: %.4f\n\n",stanDeviation);

any hint would be fantastic!! Thanks!!!

[chaarmann]

Please correct your post and use code tag to format your code.
You forgot to mention your problem. What did not work in a way you expected?

Tip:
You can reduce your code size by using arrays (or Lists) and for-loops: You should not use double day1, day2, day3 etc., but "double[] days = new double[7]" and access for example day 3 by "days[2]" ,or using a loop "for(int i=0; i < 7; i++){...}" with "day[i]"

[Rabbit]

Please use code tags when posting code.

You never assign the result of math.pow to anything. So you end up never having your squared differences. Also, your arguments need to be reversed, it's the first argument to the power of the second argument, not the reverse.