Finding the Fourth Proportional to 259,591.57, 389,385.60 and 139,704.94

Step by Step Solution

1. Step 1: Write the proportion equation
   259,591.57 : 389,385.60 = 139,704.94 : x
2. Step 2: Convert to fraction form
   259,591.57/389,385.60 = 139,704.94/x
3. Step 3: Cross multiply
   259,591.57x = 389,385.60 × 139,704.94
4. Step 4: Simplify right side
   259,591.57x = 54,399,091,884.86
5. Step 5: Solve for x
   x = 54,399,091,884.86/259,591.57
6. Step 6: Final answer
   x = 209,556.47