Finding the Fourth Proportional to 8,789.48, 12,129.56 and 5,431.53

Step by Step Solution

1. Step 1: Write the proportion equation
   8,789.48 : 12,129.56 = 5,431.53 : x
2. Step 2: Convert to fraction form
   8,789.48/12,129.56 = 5,431.53/x
3. Step 3: Cross multiply
   8,789.48x = 12,129.56 × 5,431.53
4. Step 4: Simplify right side
   8,789.48x = 65,882,041.87
5. Step 5: Solve for x
   x = 65,882,041.87/8,789.48
6. Step 6: Final answer
   x = 7,495.56