Finding the Fourth Proportional to 13,686.94, 18,887.97 and 7,399.31

Step by Step Solution

1. Step 1: Write the proportion equation
   13,686.94 : 18,887.97 = 7,399.31 : x
2. Step 2: Convert to fraction form
   13,686.94/18,887.97 = 7,399.31/x
3. Step 3: Cross multiply
   13,686.94x = 18,887.97 × 7,399.31
4. Step 4: Simplify right side
   13,686.94x = 139,758,020.27
5. Step 5: Solve for x
   x = 139,758,020.27/13,686.94
6. Step 6: Final answer
   x = 10,211.05