Finding the Fourth Proportional to 9,321.17, 12,862.68 and 5,129.42

Step by Step Solution

1. Step 1: Write the proportion equation
   9,321.17 : 12,862.68 = 5,129.42 : x
2. Step 2: Convert to fraction form
   9,321.17/12,862.68 = 5,129.42/x
3. Step 3: Cross multiply
   9,321.17x = 12,862.68 × 5,129.42
4. Step 4: Simplify right side
   9,321.17x = 65,978,088.05
5. Step 5: Solve for x
   x = 65,978,088.05/9,321.17
6. Step 6: Final answer
   x = 7,078.31