Finding the Fourth Proportional to 1,004.91, 1,508.17 and 518.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,004.91 : 1,508.17 = 518.10 : x
2. Step 2: Convert to fraction form
   1,004.91/1,508.17 = 518.10/x
3. Step 3: Cross multiply
   1,004.91x = 1,508.17 × 518.10
4. Step 4: Simplify right side
   1,004.91x = 781,376.90
5. Step 5: Solve for x
   x = 781,376.90/1,004.91
6. Step 6: Final answer
   x = 777.56