Ich weiß das ich ein Header namens iomanip benötige und setprecision(x) und
setiosflags(ios::fixed) bzw. zum Ausgeben des Wertes in der Variable setw(x);

Nun mein Code:

#include <cstdlib>
#include <iostream>
#include <conioex.h>
#include <string>
#include <time.h>
#include <windows.h>
#include <iomanip>

using namespace std;

struct temp
{
       string name;
       int alter;
       float gehalt;
};

temp feld[3];
int auswahl;

void name();
void alter();
void gehalt();

int main(int argc, char *argv[])
{

    do
    {

    setprecision(2);
    setiosflags(ios::fixed);         

    system("cls");         

    cout << "\t\t\t\t";
    cout << "Menue";

    cout << "\n\n\n\n\n";

    cout << "\n\t\t Nach Name                    <1>";
    cout << "\n\n\t\t Nach Alter                   <2>";
    cout << "\n\n\t\t Nach Gehalt                  <3>";
    cout << "\n\n\t\t Ende                         <0>";

    cout << "\n\n\n";
    cout << "\n\n\t\t Eingabe: ";
    cin >> auswahl;

    switch(auswahl)
    {
                   case 1: {
                            name();
                            break;
                            } 

                   case 2: {
                            alter();
                            break;
                            }       

                   case 3: {
                            gehalt();
                            break;
                            }            
   };

   }
   while(auswahl!=0); 

    system("PAUSE");
    return EXIT_SUCCESS;
}
//////////////////////////////////Name/////////////////////////////////////////////////////////
void name()
{

  system("cls");

              for(int x=0; x<3; x++)
              {
                   cout << x+1 << " Name: ";
                   cin >> feld[x].name;
                   cout << x+1 << " Alter: ";
                   cin >> feld[x].alter;
                   cout << x+1 << " Gehalt: ";
                   cin >> feld[x].gehalt;
                   cout << "\n\n\n";
              }

  for(int y=0; y<3; y++)
  {
        for(int j=0; j<(3-1); j++)
        {
                if(feld[j].name > feld[j+1].name)
                {
                                ////////Name////////////////////
                                string temp_name = feld[j].name;
                                feld[j].name = feld[j+1].name;
                                feld[j+1].name = temp_name ;
                                /////////Alter/////////////////
                                int temp_alter = feld[j].alter;
                                feld[j].alter = feld[j+1].alter;
                                feld[j+1].alter = temp_alter ;
                                /////////Gehalt/////////////////
                                float temp_gehalt = feld[j].gehalt;
                                feld[j].gehalt = feld[j+1].gehalt;
                                feld[j+1].gehalt = temp_gehalt ;
                }
        }

  }

  system("cls");

  gotoxy(35,2);
  cout << "Ausgabe"; 

  gotoxy(9,10);
  cout << "Name";
   gotoxy(32,10);
  cout << "Alter";
   gotoxy(55,10);
  cout << "Gehalt";

  for(int x=0; x<3; x++)
  {
  cout << "\n\n";        
  setprecision(2);
  setiosflags(ios::fixed);       
  cout << setw(12) << feld[x].name << setw(24) << feld[x].alter << setw(25) << feld[x].gehalt;
  } 

  Sleep(9000);

}

//////////////////////////////////Alter/////////////////////////////////////////////////////////
void alter()
{
 system("cls");

              for(int x=0; x<3; x++)
              {
                   cout << x+1 << " Name: ";
                   cin >> feld[x].name;
                   cout << x+1 << " Alter: ";
                   cin >> feld[x].alter;
                   cout << x+1 << " Gehalt: ";
                   cin >> feld[x].gehalt;
                   cout << "\n\n\n";
              }

  for(int y=0; y<3; y++)
  {
        for(int j=0; j<(3-1); j++)
        {
                if(feld[j].alter > feld[j+1].alter)
                {
                                ////////Name////////////////////
                                string temp_name = feld[j].name;
                                feld[j].name = feld[j+1].name;
                                feld[j+1].name = temp_name ;
                                /////////Alter/////////////////
                                int temp_alter = feld[j].alter;
                                feld[j].alter = feld[j+1].alter;
                                feld[j+1].alter = temp_alter ;
                                /////////Gehalt/////////////////
                                float temp_gehalt = feld[j].gehalt;
                                feld[j].gehalt = feld[j+1].gehalt;
                                feld[j+1].gehalt = temp_gehalt ;
                }
        }

  }

  system("cls");

  gotoxy(35,2);
  cout << "Ausgabe"; 

  gotoxy(9,10);
  cout << "Alter";
   gotoxy(33,10);
  cout << "Name";
   gotoxy(55,10);
  cout << "Gehalt";

  for(int x=0; x<3; x++)
  {
  cout << "\n\n";        
  setprecision(2);
  setiosflags(ios::fixed);            
  cout << setw(12)<< feld[x].alter << setw(24) << feld[x].name << setw(25) << feld[x].gehalt;

  } 

  Sleep(9000);
}

//////////////////////////////////Gehalt/////////////////////////////////////////////////////////
void gehalt()
{
 system("cls");

              for(int x=0; x<3; x++)
              {
                   cout << x+1 << " Name: ";
                   cin >> feld[x].name;
                   cout << x+1 << " Alter: ";
                   cin >> feld[x].alter;
                   cout << x+1 << " Gehalt: ";
                   cin >> feld[x].gehalt;
                   cout << "\n\n\n";
              }

  for(int y=0; y<3; y++)
  {
        for(int j=0; j<(3-1); j++)
        {
                if(feld[j].gehalt < feld[j+1].gehalt)
                {
                                ////////Name////////////////////
                                string temp_name = feld[j].name;
                                feld[j].name = feld[j+1].name;
                                feld[j+1].name = temp_name ;
                                /////////Alter/////////////////
                                int temp_alter = feld[j].alter;
                                feld[j].alter = feld[j+1].alter;
                                feld[j+1].alter = temp_alter ;
                                /////////Gehalt/////////////////
                                float temp_gehalt = feld[j].gehalt;
                                feld[j].gehalt = feld[j+1].gehalt;
                                feld[j+1].gehalt = temp_gehalt ;
                }
        }

  }

  system("cls");

  gotoxy(35,2);
  cout << "Ausgabe"; 

  gotoxy(9,10);
  cout << "Gehalt";
   gotoxy(33,10);
  cout << "Name";
   gotoxy(55,10);
  cout << "Alter";

  for(int x=0; x<3; x++)
  {
  cout << "\n\n";        
  setprecision(2);
  setiosflags(ios::fixed);            
  cout << setw(12) << feld[x].gehalt << setw(24) << feld[x].name << setw(25) << feld[x].alter;
  } 

  Sleep(9000);
}

Ich hoffe ihr könnt mir weiterhelfen!!!

cout << setw(12) << feld[x].name << setw(24) << feld[x].alter;
cout << setw(25) << setprecision(2) << setiosflags(ios::fixed) << feld[x].gehalt;

P.S. Das Sortieren solltest du als eigene Funktion implementieren (du kannst z.B. std::sort dafür aufrufen)