Finding the Fourth Proportional to 21,056.76, 29,045.52 and 12,553.30

Step by Step Solution

1. Step 1: Write the proportion equation
   21,056.76 : 29,045.52 = 12,553.30 : x
2. Step 2: Convert to fraction form
   21,056.76/29,045.52 = 12,553.30/x
3. Step 3: Cross multiply
   21,056.76x = 29,045.52 × 12,553.30
4. Step 4: Simplify right side
   21,056.76x = 364,617,126.22
5. Step 5: Solve for x
   x = 364,617,126.22/21,056.76
6. Step 6: Final answer
   x = 17,315.92