Finding the Fourth Proportional to 12,507.57, 18,747.86 and 8,128.17

Step by Step Solution

1. Step 1: Write the proportion equation
   12,507.57 : 18,747.86 = 8,128.17 : x
2. Step 2: Convert to fraction form
   12,507.57/18,747.86 = 8,128.17/x
3. Step 3: Cross multiply
   12,507.57x = 18,747.86 × 8,128.17
4. Step 4: Simplify right side
   12,507.57x = 152,385,752.58
5. Step 5: Solve for x
   x = 152,385,752.58/12,507.57
6. Step 6: Final answer
   x = 12,183.48