Finding the Fourth Proportional to 12,411.56, 17,121.09 and 7,865.90

Step by Step Solution

1. Step 1: Write the proportion equation
   12,411.56 : 17,121.09 = 7,865.90 : x
2. Step 2: Convert to fraction form
   12,411.56/17,121.09 = 7,865.90/x
3. Step 3: Cross multiply
   12,411.56x = 17,121.09 × 7,865.90
4. Step 4: Simplify right side
   12,411.56x = 134,672,781.83
5. Step 5: Solve for x
   x = 134,672,781.83/12,411.56
6. Step 6: Final answer
   x = 10,850.59