Finding the Fourth Proportional to 129,391.32, 178,555.83 and 72,028.76

Step by Step Solution

1. Step 1: Write the proportion equation
   129,391.32 : 178,555.83 = 72,028.76 : x
2. Step 2: Convert to fraction form
   129,391.32/178,555.83 = 72,028.76/x
3. Step 3: Cross multiply
   129,391.32x = 178,555.83 × 72,028.76
4. Step 4: Simplify right side
   129,391.32x = 12,861,155,111.92
5. Step 5: Solve for x
   x = 12,861,155,111.92/129,391.32
6. Step 6: Final answer
   x = 99,397.36