Finding the Fourth Proportional to 789,978.45, 1,185,090.57 and 257,375.55

Step by Step Solution

1. Step 1: Write the proportion equation
   789,978.45 : 1,185,090.57 = 257,375.55 : x
2. Step 2: Convert to fraction form
   789,978.45/1,185,090.57 = 257,375.55/x
3. Step 3: Cross multiply
   789,978.45x = 1,185,090.57 × 257,375.55
4. Step 4: Simplify right side
   789,978.45x = 305,013,337,253.56
5. Step 5: Solve for x
   x = 305,013,337,253.56/789,978.45
6. Step 6: Final answer
   x = 386,103.36