quad_mpi():
  FORTRAN90/MPI version
  Estimate an integral of f(x) from A to B.
  f(x) = 50 / (pi * ( 2500 * x * x + 1 ) )
 
  A        =    0.00000    
  B        =    10.0000    
  N        =      9999999
  Exact    =   0.4993633810764567    
 
  Use MPI to divide the computation among
  multiple processes.
  Process        1 contributes MY_TOTAL =   0.498098    
  Process        2 contributes MY_TOTAL =   0.954910E-03
  Process        3 contributes MY_TOTAL =   0.318308E-03
 
  Estimate =   0.4993711897633686    
  Error    =   0.780869E-05
  Time     =   0.426939E-01
 
QUAD_MPI:
  Normal end of execution.