Finding the Fourth Proportional to 13,615.97, 18,789.90 and 7,647.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,615.97 : 18,789.90 = 7,647.50 : x
2. Step 2: Convert to fraction form
   13,615.97/18,789.90 = 7,647.50/x
3. Step 3: Cross multiply
   13,615.97x = 18,789.90 × 7,647.50
4. Step 4: Simplify right side
   13,615.97x = 143,695,666.30
5. Step 5: Solve for x
   x = 143,695,666.30/13,615.97
6. Step 6: Final answer
   x = 10,553.47