Finding the Fourth Proportional to 10,485.94, 15,680.31 and 8,119.12

Step by Step Solution

1. Step 1: Write the proportion equation
   10,485.94 : 15,680.31 = 8,119.12 : x
2. Step 2: Convert to fraction form
   10,485.94/15,680.31 = 8,119.12/x
3. Step 3: Cross multiply
   10,485.94x = 15,680.31 × 8,119.12
4. Step 4: Simplify right side
   10,485.94x = 127,310,318.53
5. Step 5: Solve for x
   x = 127,310,318.53/10,485.94
6. Step 6: Final answer
   x = 12,141.05