Finding the Fourth Proportional to 13,311.72, 18,371.10 and 7,647.39

Step by Step Solution

1. Step 1: Write the proportion equation
   13,311.72 : 18,371.10 = 7,647.39 : x
2. Step 2: Convert to fraction form
   13,311.72/18,371.10 = 7,647.39/x
3. Step 3: Cross multiply
   13,311.72x = 18,371.10 × 7,647.39
4. Step 4: Simplify right side
   13,311.72x = 140,490,966.43
5. Step 5: Solve for x
   x = 140,490,966.43/13,311.72
6. Step 6: Final answer
   x = 10,553.93