Finding the Fourth Proportional to 12,778.49, 17,629.43 and 9,429.30

Step by Step Solution

1. Step 1: Write the proportion equation
   12,778.49 : 17,629.43 = 9,429.30 : x
2. Step 2: Convert to fraction form
   12,778.49/17,629.43 = 9,429.30/x
3. Step 3: Cross multiply
   12,778.49x = 17,629.43 × 9,429.30
4. Step 4: Simplify right side
   12,778.49x = 166,233,137.15
5. Step 5: Solve for x
   x = 166,233,137.15/12,778.49
6. Step 6: Final answer
   x = 13,008.82