Finding the Fourth Proportional to 8,580.96, 12,864.12 and 8,172.72

Step by Step Solution

1. Step 1: Write the proportion equation
   8,580.96 : 12,864.12 = 8,172.72 : x
2. Step 2: Convert to fraction form
   8,580.96/12,864.12 = 8,172.72/x
3. Step 3: Cross multiply
   8,580.96x = 12,864.12 × 8,172.72
4. Step 4: Simplify right side
   8,580.96x = 105,134,850.81
5. Step 5: Solve for x
   x = 105,134,850.81/8,580.96
6. Step 6: Final answer
   x = 12,252.11