Finding the Fourth Proportional to 8,980.47, 12,405.15 and 8,142.12

Step by Step Solution

1. Step 1: Write the proportion equation
   8,980.47 : 12,405.15 = 8,142.12 : x
2. Step 2: Convert to fraction form
   8,980.47/12,405.15 = 8,142.12/x
3. Step 3: Cross multiply
   8,980.47x = 12,405.15 × 8,142.12
4. Step 4: Simplify right side
   8,980.47x = 101,004,219.92
5. Step 5: Solve for x
   x = 101,004,219.92/8,980.47
6. Step 6: Final answer
   x = 11,247.10