Finding the Fourth Proportional to 8,900.72, 12,282.12 and 4,921.20

Step by Step Solution

1. Step 1: Write the proportion equation
   8,900.72 : 12,282.12 = 4,921.20 : x
2. Step 2: Convert to fraction form
   8,900.72/12,282.12 = 4,921.20/x
3. Step 3: Cross multiply
   8,900.72x = 12,282.12 × 4,921.20
4. Step 4: Simplify right side
   8,900.72x = 60,442,768.94
5. Step 5: Solve for x
   x = 60,442,768.94/8,900.72
6. Step 6: Final answer
   x = 6,790.77