Finding the Fourth Proportional to 86,406.72, 129,411.36 and 72,111.84

Step by Step Solution

1. Step 1: Write the proportion equation
   86,406.72 : 129,411.36 = 72,111.84 : x
2. Step 2: Convert to fraction form
   86,406.72/129,411.36 = 72,111.84/x
3. Step 3: Cross multiply
   86,406.72x = 129,411.36 × 72,111.84
4. Step 4: Simplify right side
   86,406.72x = 9,332,091,286.50
5. Step 5: Solve for x
   x = 9,332,091,286.50/86,406.72
6. Step 6: Final answer
   x = 108,001.92