Finding the Fourth Proportional to 511,978.58, 768,439.55 and 259,437.98

Step by Step Solution

1. Step 1: Write the proportion equation
   511,978.58 : 768,439.55 = 259,437.98 : x
2. Step 2: Convert to fraction form
   511,978.58/768,439.55 = 259,437.98/x
3. Step 3: Cross multiply
   511,978.58x = 768,439.55 × 259,437.98
4. Step 4: Simplify right side
   511,978.58x = 199,362,399,464.72
5. Step 5: Solve for x
   x = 199,362,399,464.72/511,978.58
6. Step 6: Final answer
   x = 389,395.98