求方差

#include <stdio.h>#include <iostream>using namespace std;double Variance(int * d, int n); // 方差int main(){int a[5] = {4, 5, 7, 9, 10};printf("%6.3f/n", Variance(a, 5));return 0;}double Variance(int * d, int n) // 方差{double avg, sum = 0;int i;for (i = 0; i < n; ++i) {sum += (double)d[i];}avg = sum / n;sum = 0;for (i = 0; i < n; ++i) {sum += (d[i] - avg) * (d[i] - avg);}sum /= n;return sum;}