Finding the Fourth Proportional to 21,003.70, 31,469.10 and 13,604.35

Step by Step Solution

1. Step 1: Write the proportion equation
   21,003.70 : 31,469.10 = 13,604.35 : x
2. Step 2: Convert to fraction form
   21,003.70/31,469.10 = 13,604.35/x
3. Step 3: Cross multiply
   21,003.70x = 31,469.10 × 13,604.35
4. Step 4: Simplify right side
   21,003.70x = 428,116,650.59
5. Step 5: Solve for x
   x = 428,116,650.59/21,003.70
6. Step 6: Final answer
   x = 20,382.92