Finding the Fourth Proportional to 660,631.76, 990,942.17 and 392,617.34

Step by Step Solution

1. Step 1: Write the proportion equation
   660,631.76 : 990,942.17 = 392,617.34 : x
2. Step 2: Convert to fraction form
   660,631.76/990,942.17 = 392,617.34/x
3. Step 3: Cross multiply
   660,631.76x = 990,942.17 × 392,617.34
4. Step 4: Simplify right side
   660,631.76x = 389,061,071,961.43
5. Step 5: Solve for x
   x = 389,061,071,961.43/660,631.76
6. Step 6: Final answer
   x = 588,922.75