Finding the Fourth Proportional to 12,892.91, 17,792.20 and 7,857.15

Step by Step Solution

1. Step 1: Write the proportion equation
   12,892.91 : 17,792.20 = 7,857.15 : x
2. Step 2: Convert to fraction form
   12,892.91/17,792.20 = 7,857.15/x
3. Step 3: Cross multiply
   12,892.91x = 17,792.20 × 7,857.15
4. Step 4: Simplify right side
   12,892.91x = 139,795,944.94
5. Step 5: Solve for x
   x = 139,795,944.94/12,892.91
6. Step 6: Final answer
   x = 10,842.85