Finding the Fourth Proportional to 13,399.26, 18,477.83 and 12,339.78

Step by Step Solution

1. Step 1: Write the proportion equation
   13,399.26 : 18,477.83 = 12,339.78 : x
2. Step 2: Convert to fraction form
   13,399.26/18,477.83 = 12,339.78/x
3. Step 3: Cross multiply
   13,399.26x = 18,477.83 × 12,339.78
4. Step 4: Simplify right side
   13,399.26x = 228,012,295.38
5. Step 5: Solve for x
   x = 228,012,295.38/13,399.26
6. Step 6: Final answer
   x = 17,016.78