Finding the Fourth Proportional to 8,401.28, 12,589.48 and 7,478.56

Step by Step Solution

1. Step 1: Write the proportion equation
   8,401.28 : 12,589.48 = 7,478.56 : x
2. Step 2: Convert to fraction form
   8,401.28/12,589.48 = 7,478.56/x
3. Step 3: Cross multiply
   8,401.28x = 12,589.48 × 7,478.56
4. Step 4: Simplify right side
   8,401.28x = 94,151,181.55
5. Step 5: Solve for x
   x = 94,151,181.55/8,401.28
6. Step 6: Final answer
   x = 11,206.77