Finding the Fourth Proportional to 12,898.47, 17,797.17 and 8,428.80

Step by Step Solution

1. Step 1: Write the proportion equation
   12,898.47 : 17,797.17 = 8,428.80 : x
2. Step 2: Convert to fraction form
   12,898.47/17,797.17 = 8,428.80/x
3. Step 3: Cross multiply
   12,898.47x = 17,797.17 × 8,428.80
4. Step 4: Simplify right side
   12,898.47x = 150,008,786.50
5. Step 5: Solve for x
   x = 150,008,786.50/12,898.47
6. Step 6: Final answer
   x = 11,629.97