Finding the Fourth Proportional to 13,431.83, 20,139.59 and 5,112.41

Step by Step Solution

1. Step 1: Write the proportion equation
   13,431.83 : 20,139.59 = 5,112.41 : x
2. Step 2: Convert to fraction form
   13,431.83/20,139.59 = 5,112.41/x
3. Step 3: Cross multiply
   13,431.83x = 20,139.59 × 5,112.41
4. Step 4: Simplify right side
   13,431.83x = 102,961,753.39
5. Step 5: Solve for x
   x = 102,961,753.39/13,431.83
6. Step 6: Final answer
   x = 7,665.51