Finding the Fourth Proportional to 428,931.09, 642,978.17 and 204,231.15

Step by Step Solution

1. Step 1: Write the proportion equation
   428,931.09 : 642,978.17 = 204,231.15 : x
2. Step 2: Convert to fraction form
   428,931.09/642,978.17 = 204,231.15/x
3. Step 3: Cross multiply
   428,931.09x = 642,978.17 × 204,231.15
4. Step 4: Simplify right side
   428,931.09x = 131,316,171,084.00
5. Step 5: Solve for x
   x = 131,316,171,084.00/428,931.09
6. Step 6: Final answer
   x = 306,147.48