Finding the Fourth Proportional to 21,139.38, 29,172.76 and 12,185.37

Step by Step Solution

1. Step 1: Write the proportion equation
   21,139.38 : 29,172.76 = 12,185.37 : x
2. Step 2: Convert to fraction form
   21,139.38/29,172.76 = 12,185.37/x
3. Step 3: Cross multiply
   21,139.38x = 29,172.76 × 12,185.37
4. Step 4: Simplify right side
   21,139.38x = 355,480,844.06
5. Step 5: Solve for x
   x = 355,480,844.06/21,139.38
6. Step 6: Final answer
   x = 16,816.05