Finding the Fourth Proportional to 1,339.82, 2,009.81 and 518.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,339.82 : 2,009.81 = 518.10 : x
2. Step 2: Convert to fraction form
   1,339.82/2,009.81 = 518.10/x
3. Step 3: Cross multiply
   1,339.82x = 2,009.81 × 518.10
4. Step 4: Simplify right side
   1,339.82x = 1,041,272.51
5. Step 5: Solve for x
   x = 1,041,272.51/1,339.82
6. Step 6: Final answer
   x = 777.17