Finding the Fourth Proportional to 8,521.28, 12,766.56 and 7,133.12

Step by Step Solution

1. Step 1: Write the proportion equation
   8,521.28 : 12,766.56 = 7,133.12 : x
2. Step 2: Convert to fraction form
   8,521.28/12,766.56 = 7,133.12/x
3. Step 3: Cross multiply
   8,521.28x = 12,766.56 × 7,133.12
4. Step 4: Simplify right side
   8,521.28x = 91,065,404.47
5. Step 5: Solve for x
   x = 91,065,404.47/8,521.28
6. Step 6: Final answer
   x = 10,686.82