Finding the Fourth Proportional to 20,665.59, 30,987 and 12,235.62

Step by Step Solution

1. Step 1: Write the proportion equation
   20,665.59 : 30,987 = 12,235.62 : x
2. Step 2: Convert to fraction form
   20,665.59/30,987 = 12,235.62/x
3. Step 3: Cross multiply
   20,665.59x = 30,987 × 12,235.62
4. Step 4: Simplify right side
   20,665.59x = 379,145,156.94
5. Step 5: Solve for x
   x = 379,145,156.94/20,665.59
6. Step 6: Final answer
   x = 18,346.69