Finding the Fourth Proportional to 18,128.86, 25,036.84 and 12,478.20

Step by Step Solution

1. Step 1: Write the proportion equation
   18,128.86 : 25,036.84 = 12,478.20 : x
2. Step 2: Convert to fraction form
   18,128.86/25,036.84 = 12,478.20/x
3. Step 3: Cross multiply
   18,128.86x = 25,036.84 × 12,478.20
4. Step 4: Simplify right side
   18,128.86x = 312,414,696.89
5. Step 5: Solve for x
   x = 312,414,696.89/18,128.86
6. Step 6: Final answer
   x = 17,233.00