Finding the Fourth Proportional to 9,321.56, 12,863.76 and 5,129.81

Step by Step Solution

1. Step 1: Write the proportion equation
   9,321.56 : 12,863.76 = 5,129.81 : x
2. Step 2: Convert to fraction form
   9,321.56/12,863.76 = 5,129.81/x
3. Step 3: Cross multiply
   9,321.56x = 12,863.76 × 5,129.81
4. Step 4: Simplify right side
   9,321.56x = 65,988,676.85
5. Step 5: Solve for x
   x = 65,988,676.85/9,321.56
6. Step 6: Final answer
   x = 7,079.14