Finding the Fourth Proportional to 30,787.89, 42,487.20 and 16,640.70

Step by Step Solution

1. Step 1: Write the proportion equation
   30,787.89 : 42,487.20 = 16,640.70 : x
2. Step 2: Convert to fraction form
   30,787.89/42,487.20 = 16,640.70/x
3. Step 3: Cross multiply
   30,787.89x = 42,487.20 × 16,640.70
4. Step 4: Simplify right side
   30,787.89x = 707,016,749.04
5. Step 5: Solve for x
   x = 707,016,749.04/30,787.89
6. Step 6: Final answer
   x = 22,964.12