Finding the Fourth Proportional to 8,862.72, 12,231.68 and 5,555.20

Step by Step Solution

1. Step 1: Write the proportion equation
   8,862.72 : 12,231.68 = 5,555.20 : x
2. Step 2: Convert to fraction form
   8,862.72/12,231.68 = 5,555.20/x
3. Step 3: Cross multiply
   8,862.72x = 12,231.68 × 5,555.20
4. Step 4: Simplify right side
   8,862.72x = 67,949,428.74
5. Step 5: Solve for x
   x = 67,949,428.74/8,862.72
6. Step 6: Final answer
   x = 7,666.88