Program code needed.

Please give the program code of this problems:

1. Enter a number (x) and get the average of all numbers from 1 to x.
2. Enter a number (x) and print the factorial of the number.
Program will look like this:
Enter value: 4
4 24
-Exit when the value entered is zero (0).
factorial = (n)*(n-1)*(n-2)
ex: 4!=4*3*2*1

* I dont have any clue on number 2 on how to do it.
*This two numbers need a loop (for).
* I tried number 1 but it's not right, anyway here is the program code i did:
#include <stdio.h>
#include <conio.h>
int main()
{
int x,y;
float z;
clrscr();
printf ("\nEnter a number:\t");
scanf ("%d",&x);
for (y=z;y>0;y--);
z=(y+z)/(x);
printf ("\n\nThe average of all numbers from 1 to %d is %f",x,z);
getch();
return(0);
}


*THANKS in advance.