Finding the Fourth Proportional to 259,591.50, 389,385.47 and 139,704.84

Step by Step Solution

1. Step 1: Write the proportion equation
   259,591.50 : 389,385.47 = 139,704.84 : x
2. Step 2: Convert to fraction form
   259,591.50/389,385.47 = 139,704.84/x
3. Step 3: Cross multiply
   259,591.50x = 389,385.47 × 139,704.84
4. Step 4: Simplify right side
   259,591.50x = 54,399,034,086.15
5. Step 5: Solve for x
   x = 54,399,034,086.15/259,591.50
6. Step 6: Final answer
   x = 209,556.30