Finding the Fourth Proportional to 8,789.12, 12,129.20 and 5,434.24

Step by Step Solution

1. Step 1: Write the proportion equation
   8,789.12 : 12,129.20 = 5,434.24 : x
2. Step 2: Convert to fraction form
   8,789.12/12,129.20 = 5,434.24/x
3. Step 3: Cross multiply
   8,789.12x = 12,129.20 × 5,434.24
4. Step 4: Simplify right side
   8,789.12x = 65,912,983.81
5. Step 5: Solve for x
   x = 65,912,983.81/8,789.12
6. Step 6: Final answer
   x = 7,499.38