Finding the Fourth Proportional to 21,451.59, 29,604.57 and 12,021.57

Step by Step Solution

1. Step 1: Write the proportion equation
   21,451.59 : 29,604.57 = 12,021.57 : x
2. Step 2: Convert to fraction form
   21,451.59/29,604.57 = 12,021.57/x
3. Step 3: Cross multiply
   21,451.59x = 29,604.57 × 12,021.57
4. Step 4: Simplify right side
   21,451.59x = 355,893,410.57
5. Step 5: Solve for x
   x = 355,893,410.57/21,451.59
6. Step 6: Final answer
   x = 16,590.54