Finding the Fourth Proportional to 13,105.89, 18,086.34 and 7,137.55

Step by Step Solution

1. Step 1: Write the proportion equation
   13,105.89 : 18,086.34 = 7,137.55 : x
2. Step 2: Convert to fraction form
   13,105.89/18,086.34 = 7,137.55/x
3. Step 3: Cross multiply
   13,105.89x = 18,086.34 × 7,137.55
4. Step 4: Simplify right side
   13,105.89x = 129,092,120.38
5. Step 5: Solve for x
   x = 129,092,120.38/13,105.89
6. Step 6: Final answer
   x = 9,849.93