Finding the Fourth Proportional to 518,859, 716,026.38 and 280,395

Step by Step Solution

1. Step 1: Write the proportion equation
   518,859 : 716,026.38 = 280,395 : x
2. Step 2: Convert to fraction form
   518,859/716,026.38 = 280,395/x
3. Step 3: Cross multiply
   518,859x = 716,026.38 × 280,395
4. Step 4: Simplify right side
   518,859x = 200,770,216,820.10
5. Step 5: Solve for x
   x = 200,770,216,820.10/518,859
6. Step 6: Final answer
   x = 386,945.62