Finding the Fourth Proportional to 21,435.12, 29,580.54 and 12,488.76

Step by Step Solution

1. Step 1: Write the proportion equation
   21,435.12 : 29,580.54 = 12,488.76 : x
2. Step 2: Convert to fraction form
   21,435.12/29,580.54 = 12,488.76/x
3. Step 3: Cross multiply
   21,435.12x = 29,580.54 × 12,488.76
4. Step 4: Simplify right side
   21,435.12x = 369,424,264.73
5. Step 5: Solve for x
   x = 369,424,264.73/21,435.12
6. Step 6: Final answer
   x = 17,234.53