To get familiarity with arrays in C I'm trying to write a simple program to calculate average, standard deviation, and bubblesort from some numbers passed into an array. Yet I keep running into the same error in my average and stddev functions... It says "practice.c:X: error: lvalue required as left operand of assignment" AND

"practice.c:X: error: incompatible types when returning type ‘double (*)(int *, int)’ but ‘double’ was expected"

I feel that this is a very simple problem, but I am stumped.

Thanks!

#include <stdio.h> #include <math.h> #include <stdlib.h> const int SIZE = 10; //average double average(int x[], int SIZE) { double total = 0.0; int i; for (i=0; i < SIZE; i++) { total += x[i]; } average = total / (SIZE-1); return average; } //standard deviation double stddev(int x[], int SIZE, double average) { double total = 0.0; int i; for(i=0; i < 100; i++) { total += (average - x[i]) * (average - x[i]); } stddev = sqrt(total/(SIZE-1)); return stddev; } //bubblesort void bubblesort(int x[], int SIZE) { int i; int j; int k; for(i = 0; i < (SIZE - 1); i++){ for(j = 0; j < (SIZE -1); j++){ if(x[j] > x[j + 1]){ k = x[j]; x[j] = x[j+1]; x[j+1] = k; } } printf("%d", x[i]); } int main(void) { int i = 0; for(i = 0; i <= 10; i++) { scanf("%d", &x[i]); printf("%d\n", x[i]); } }