Finding the Fourth Proportional to 388,510.98, 582,870.15 and 139,218.18

Step by Step Solution

1. Step 1: Write the proportion equation
   388,510.98 : 582,870.15 = 139,218.18 : x
2. Step 2: Convert to fraction form
   388,510.98/582,870.15 = 139,218.18/x
3. Step 3: Cross multiply
   388,510.98x = 582,870.15 × 139,218.18
4. Step 4: Simplify right side
   388,510.98x = 81,146,121,459.33
5. Step 5: Solve for x
   x = 81,146,121,459.33/388,510.98
6. Step 6: Final answer
   x = 208,864.42