Finding the Fourth Proportional to 12,728.50, 17,565.36 and 7,760.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,728.50 : 17,565.36 = 7,760.50 : x
2. Step 2: Convert to fraction form
   12,728.50/17,565.36 = 7,760.50/x
3. Step 3: Cross multiply
   12,728.50x = 17,565.36 × 7,760.50
4. Step 4: Simplify right side
   12,728.50x = 136,315,976.28
5. Step 5: Solve for x
   x = 136,315,976.28/12,728.50
6. Step 6: Final answer
   x = 10,709.51