Finding the Fourth Proportional to 18,640.49, 25,724.39 and 10,142.69

Step by Step Solution

1. Step 1: Write the proportion equation
   18,640.49 : 25,724.39 = 10,142.69 : x
2. Step 2: Convert to fraction form
   18,640.49/25,724.39 = 10,142.69/x
3. Step 3: Cross multiply
   18,640.49x = 25,724.39 × 10,142.69
4. Step 4: Simplify right side
   18,640.49x = 260,914,333.87
5. Step 5: Solve for x
   x = 260,914,333.87/18,640.49
6. Step 6: Final answer
   x = 13,997.19