Finding the Fourth Proportional to 20,487.12, 30,699.24 and 12,150.72

Step by Step Solution

1. Step 1: Write the proportion equation
   20,487.12 : 30,699.24 = 12,150.72 : x
2. Step 2: Convert to fraction form
   20,487.12/30,699.24 = 12,150.72/x
3. Step 3: Cross multiply
   20,487.12x = 30,699.24 × 12,150.72
4. Step 4: Simplify right side
   20,487.12x = 373,017,869.45
5. Step 5: Solve for x
   x = 373,017,869.45/20,487.12
6. Step 6: Final answer
   x = 18,207.43