Finding the Fourth Proportional to 9,420.43, 12,967.57 and 8,143.72

Step by Step Solution

1. Step 1: Write the proportion equation
   9,420.43 : 12,967.57 = 8,143.72 : x
2. Step 2: Convert to fraction form
   9,420.43/12,967.57 = 8,143.72/x
3. Step 3: Cross multiply
   9,420.43x = 12,967.57 × 8,143.72
4. Step 4: Simplify right side
   9,420.43x = 105,604,259.16
5. Step 5: Solve for x
   x = 105,604,259.16/9,420.43
6. Step 6: Final answer
   x = 11,210.13