Simple averages

Hi i have an array i by j big

and i want to work out averages per row and per column individually and allow the user to chose:

desired output::::
Print averages for:
1) days
2) weeks
(user then picks one... lets say days)
Average days:
Day1= 23.44
Day2= 34.56
and so on.

the days are the rows of the array and the weeks are the column of the arrays.
Here is the function that for my avrages:

Code:

Average()         {
          int z,x,w;
          float avg_d,avg_w,t,f;
          printf (" Print averages for:\n\t1.Days\n\t2.Weeks\n\n");
          scanf ("%d",z);
 if (z=1)
 {printf ("Average Days:\n\n");
 for(x=0; x<=i;x++)
 {
 for(w=0;w=j;w++)
                  {
                  t+=array[x][w];
                  }
                  avg_d=(t/j);
   printf("\tDay%d=%.2f\n",x,avg_d);
   }
}
if (z=2) 
{printf ("Average Week:\n\n");
        {for(w=0;w=j;w++)
                         {
                          for(x=0; x<=i;x++)
                              { 
                                f+=array[x][w]; 
                                  }
                           avg_w=(f/7);
                         printf ("\tWeek%d=%.2f",w,avg_w);
            }
            }         
}
}

thanks for your time and help