jm

public class cpk {

    int a = 0;
    int count = 0;
    int total = 0;
    int total2 = 0;
    double average = 0;
    double r2 = 0;
    double sd = 0;

    public cpk() {
    }

    public void calculate(String s) {
        while (scanf("%d", &  a) == 1) {
            total += a;
            total2 += a * a;
            count++;
        }
        if (count == 0) {
            System.out.println("No Input data");
            return;
        }
        average = total / count;
        System.out.println("Average value us %4.1f" + average);
        if (count == 1) {
            System.out.println("can calculate standard deviation with one data");
            return;
        }

        r2 = total2 - 2 * average * total + average * count;
        sd = sqrt(r2 / (count - 1));
        System.out.println("Average value us %4.1f" + sd);
        return;

    }
}