Finding the Fourth Proportional to 861,580.18, 1,291,488.18 and 388,597.69

Step by Step Solution

1. Step 1: Write the proportion equation
   861,580.18 : 1,291,488.18 = 388,597.69 : x
2. Step 2: Convert to fraction form
   861,580.18/1,291,488.18 = 388,597.69/x
3. Step 3: Cross multiply
   861,580.18x = 1,291,488.18 × 388,597.69
4. Step 4: Simplify right side
   861,580.18x = 501,869,323,410.30
5. Step 5: Solve for x
   x = 501,869,323,410.30/861,580.18
6. Step 6: Final answer
   x = 582,498.69