Finding the Fourth Proportional to 518,498.50, 715,528.20 and 280,034.50

Step by Step Solution

1. Step 1: Write the proportion equation
   518,498.50 : 715,528.20 = 280,034.50 : x
2. Step 2: Convert to fraction form
   518,498.50/715,528.20 = 280,034.50/x
3. Step 3: Cross multiply
   518,498.50x = 715,528.20 × 280,034.50
4. Step 4: Simplify right side
   518,498.50x = 200,372,581,722.90
5. Step 5: Solve for x
   x = 200,372,581,722.90/518,498.50
6. Step 6: Final answer
   x = 386,447.76