Finding the Fourth Proportional to 11,385.98, 15,727.59 and 8,728.77

Step by Step Solution

1. Step 1: Write the proportion equation
   11,385.98 : 15,727.59 = 8,728.77 : x
2. Step 2: Convert to fraction form
   11,385.98/15,727.59 = 8,728.77/x
3. Step 3: Cross multiply
   11,385.98x = 15,727.59 × 8,728.77
4. Step 4: Simplify right side
   11,385.98x = 137,282,515.76
5. Step 5: Solve for x
   x = 137,282,515.76/11,385.98
6. Step 6: Final answer
   x = 12,057.15