Finding the Fourth Proportional to 129,898.21, 179,243.72 and 72,540.72

Step by Step Solution

1. Step 1: Write the proportion equation
   129,898.21 : 179,243.72 = 72,540.72 : x
2. Step 2: Convert to fraction form
   129,898.21/179,243.72 = 72,540.72/x
3. Step 3: Cross multiply
   129,898.21x = 179,243.72 × 72,540.72
4. Step 4: Simplify right side
   129,898.21x = 13,002,468,467.57
5. Step 5: Solve for x
   x = 13,002,468,467.57/129,898.21
6. Step 6: Final answer
   x = 100,097.36