Finding the Fourth Proportional to 18,419.39, 25,428.42 and 12,401.31

Step by Step Solution

1. Step 1: Write the proportion equation
   18,419.39 : 25,428.42 = 12,401.31 : x
2. Step 2: Convert to fraction form
   18,419.39/25,428.42 = 12,401.31/x
3. Step 3: Cross multiply
   18,419.39x = 25,428.42 × 12,401.31
4. Step 4: Simplify right side
   18,419.39x = 315,345,719.23
5. Step 5: Solve for x
   x = 315,345,719.23/18,419.39
6. Step 6: Final answer
   x = 17,120.32