Finding the Fourth Proportional to 658,978.71, 987,066.42 and 388,815.70

Step by Step Solution

1. Step 1: Write the proportion equation
   658,978.71 : 987,066.42 = 388,815.70 : x
2. Step 2: Convert to fraction form
   658,978.71/987,066.42 = 388,815.70/x
3. Step 3: Cross multiply
   658,978.71x = 987,066.42 × 388,815.70
4. Step 4: Simplify right side
   658,978.71x = 383,786,921,038.79
5. Step 5: Solve for x
   x = 383,786,921,038.79/658,978.71
6. Step 6: Final answer
   x = 582,396.54