Finding the Fourth Proportional to 21,143.72, 31,712.83 and 7,994.38

Step by Step Solution

1. Step 1: Write the proportion equation
   21,143.72 : 31,712.83 = 7,994.38 : x
2. Step 2: Convert to fraction form
   21,143.72/31,712.83 = 7,994.38/x
3. Step 3: Cross multiply
   21,143.72x = 31,712.83 × 7,994.38
4. Step 4: Simplify right side
   21,143.72x = 253,524,413.90
5. Step 5: Solve for x
   x = 253,524,413.90/21,143.72
6. Step 6: Final answer
   x = 11,990.53