1 // Calculates the arithmetic mean of a certain amount of 2 // numbers. First ask for the quantity and then calculates 3 // it and prints it; 4 5 #include <stdio.h> 6 #include <stdlib.h> 7 #include <math.h> 8 9 #define MAX_LEN 20 10 11 int main (void) { 12 13 int i, n; 14 float d, x, suma, numbers[MAX_LEN]; 15 char buffer[MAX_LEN]; 16 17 // Read the quantity of numbers to mean; 18 if(fgets(buffer, sizeof(int) + 1, stdin) != NULL) 19 n = atoi(buffer); 20 else return 1; 21 22 // Read the values to mean and stores it on numbers; 23 for(i = 0, suma = 0; i < n; i++) { 24 if(fgets(buffer, sizeof(int) + 1, stdin) != NULL) { 25 numbers[i] = atof(buffer); 26 suma += numbers[i]; 27 } else return 1; 28 } 29 30 // Calculate the arithmetic mean and stores it on x; 31 x = ((1 / (float)n) * suma); 32 33 // Calculates the standard deviation; 34 for(i = 0; i < n; i++) { 35 suma += (numbers[i] - x); 36 d = sqrtf((1/n) * powf(suma, 2.0)); 37 } 38 39 // Print the arithmetic mean; 40 printf("x = %.3f\n", x); 41 42 // Print the standard deviation; 43 printf("d = %.3f\n", d); 44 return 0; 45 }
