Finding the Fourth Proportional to 12,411.70, 17,121.20 and 7,628.31

Step by Step Solution

1. Step 1: Write the proportion equation
   12,411.70 : 17,121.20 = 7,628.31 : x
2. Step 2: Convert to fraction form
   12,411.70/17,121.20 = 7,628.31/x
3. Step 3: Cross multiply
   12,411.70x = 17,121.20 × 7,628.31
4. Step 4: Simplify right side
   12,411.70x = 130,605,821.17
5. Step 5: Solve for x
   x = 130,605,821.17/12,411.70
6. Step 6: Final answer
   x = 10,522.80