Finding the Fourth Proportional to 12,942.72, 19,381.14 and 8,553.60

Step by Step Solution

1. Step 1: Write the proportion equation
   12,942.72 : 19,381.14 = 8,553.60 : x
2. Step 2: Convert to fraction form
   12,942.72/19,381.14 = 8,553.60/x
3. Step 3: Cross multiply
   12,942.72x = 19,381.14 × 8,553.60
4. Step 4: Simplify right side
   12,942.72x = 165,778,519.10
5. Step 5: Solve for x
   x = 165,778,519.10/12,942.72
6. Step 6: Final answer
   x = 12,808.63