Finding the Fourth Proportional to 12,390.37, 18,561.26 and 7,185.31

Step by Step Solution

1. Step 1: Write the proportion equation
   12,390.37 : 18,561.26 = 7,185.31 : x
2. Step 2: Convert to fraction form
   12,390.37/18,561.26 = 7,185.31/x
3. Step 3: Cross multiply
   12,390.37x = 18,561.26 × 7,185.31
4. Step 4: Simplify right side
   12,390.37x = 133,368,371.16
5. Step 5: Solve for x
   x = 133,368,371.16/12,390.37
6. Step 6: Final answer
   x = 10,763.87