Finding the Fourth Proportional to 12,419, 17,129.54 and 8,168.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,419 : 17,129.54 = 8,168.72 : x
2. Step 2: Convert to fraction form
   12,419/17,129.54 = 8,168.72/x
3. Step 3: Cross multiply
   12,419x = 17,129.54 × 8,168.72
4. Step 4: Simplify right side
   12,419x = 139,926,415.99
5. Step 5: Solve for x
   x = 139,926,415.99/12,419
6. Step 6: Final answer
   x = 11,267.12