Finding the Fourth Proportional to 18,139.50, 25,031.88 and 10,971.18

Step by Step Solution

1. Step 1: Write the proportion equation
   18,139.50 : 25,031.88 = 10,971.18 : x
2. Step 2: Convert to fraction form
   18,139.50/25,031.88 = 10,971.18/x
3. Step 3: Cross multiply
   18,139.50x = 25,031.88 × 10,971.18
4. Step 4: Simplify right side
   18,139.50x = 274,629,261.22
5. Step 5: Solve for x
   x = 274,629,261.22/18,139.50
6. Step 6: Final answer
   x = 15,139.85