Finding the Fourth Proportional to 12,488.60, 18,732.46 and 3,128.69

Step by Step Solution

1. Step 1: Write the proportion equation
   12,488.60 : 18,732.46 = 3,128.69 : x
2. Step 2: Convert to fraction form
   12,488.60/18,732.46 = 3,128.69/x
3. Step 3: Cross multiply
   12,488.60x = 18,732.46 × 3,128.69
4. Step 4: Simplify right side
   12,488.60x = 58,608,107.11
5. Step 5: Solve for x
   x = 58,608,107.11/12,488.60
6. Step 6: Final answer
   x = 4,692.93