Finding the Fourth Proportional to 259,695.05, 390,227.55 and 139,840.61

Step by Step Solution

1. Step 1: Write the proportion equation
   259,695.05 : 390,227.55 = 139,840.61 : x
2. Step 2: Convert to fraction form
   259,695.05/390,227.55 = 139,840.61/x
3. Step 3: Cross multiply
   259,695.05x = 390,227.55 × 139,840.61
4. Step 4: Simplify right side
   259,695.05x = 54,569,659,606.37
5. Step 5: Solve for x
   x = 54,569,659,606.37/259,695.05
6. Step 6: Final answer
   x = 210,129.76