Finding the Fourth Proportional to 21,487, 29,655.30 and 13,108.36

Step by Step Solution

1. Step 1: Write the proportion equation
   21,487 : 29,655.30 = 13,108.36 : x
2. Step 2: Convert to fraction form
   21,487/29,655.30 = 13,108.36/x
3. Step 3: Cross multiply
   21,487x = 29,655.30 × 13,108.36
4. Step 4: Simplify right side
   21,487x = 388,732,348.31
5. Step 5: Solve for x
   x = 388,732,348.31/21,487
6. Step 6: Final answer
   x = 18,091.51