Finding the Fourth Proportional to 9,162.10, 12,644.30 and 5,129.31

Step by Step Solution

1. Step 1: Write the proportion equation
   9,162.10 : 12,644.30 = 5,129.31 : x
2. Step 2: Convert to fraction form
   9,162.10/12,644.30 = 5,129.31/x
3. Step 3: Cross multiply
   9,162.10x = 12,644.30 × 5,129.31
4. Step 4: Simplify right side
   9,162.10x = 64,856,523.55
5. Step 5: Solve for x
   x = 64,856,523.55/9,162.10
6. Step 6: Final answer
   x = 7,078.79