r = (xysum - xsum*ysum) / (sqrt((n*x2sum - xsum*xsum)*(n*y2sum - ysum*ysum)));
x | y |
34.22 | 102.43 |
39.87 | 100.93 |
41.85 | 97.43 |
43.23 | 97.81 |
40.06 | 98.32 |
53.29 | 98.32 |
53.29 | 100.07 |
54.14 | 97.08 |
49.12 | 91.59 |
40.71 | 94.85 |
55.15 | 94.65 |
#include<stdio.h>
#include<conio.h>
#include<math.h>
int main()
{
float x[11][2] = {
34.22, 102.43,
39.87, 100.93,
41.85, 97.43,
43.23, 97.81,
40.06, 98.32,
53.29, 98.32,
53.29, 100.07,
49.12, 91.59,
40.71, 94.85,
55.15, 94.65,
},
xysum = 0, xsum = 0, ysum = 0, x2sum = 0, y2sum = 0, n = 11, r;
int i;
for (i = 0; i<11; i++)
{
xsum = xsum + x[i][0];
ysum = ysum + x[i][0];
xysum = xysum + x[i][0] * x[i][1];
x2sum = x2sum + x[i][0] * x[i][0];
y2sum = y2sum + x[i][1] * x[i][1];
}
r = (xysum - xsum*ysum) / (sqrt((n*x2sum - xsum*xsum)*(n*y2sum - ysum*ysum)));
printf("Coefficient of correlation (r) = %f", r);
_getch();
return 0;
}