Finding the Fourth Proportional to 129,500.37, 178,686.81 and 72,138.27

Step by Step Solution

1. Step 1: Write the proportion equation
   129,500.37 : 178,686.81 = 72,138.27 : x
2. Step 2: Convert to fraction form
   129,500.37/178,686.81 = 72,138.27/x
3. Step 3: Cross multiply
   129,500.37x = 178,686.81 × 72,138.27
4. Step 4: Simplify right side
   129,500.37x = 12,890,157,345.22
5. Step 5: Solve for x
   x = 12,890,157,345.22/129,500.37
6. Step 6: Final answer
   x = 99,537.61