Finding the Fourth Proportional to 12,389.73, 18,591.21 and 5,815.98

Step by Step Solution

1. Step 1: Write the proportion equation
   12,389.73 : 18,591.21 = 5,815.98 : x
2. Step 2: Convert to fraction form
   12,389.73/18,591.21 = 5,815.98/x
3. Step 3: Cross multiply
   12,389.73x = 18,591.21 × 5,815.98
4. Step 4: Simplify right side
   12,389.73x = 108,126,105.54
5. Step 5: Solve for x
   x = 108,126,105.54/12,389.73
6. Step 6: Final answer
   x = 8,727.08