Finding the Fourth Proportional to 9,315.52, 12,857.25 and 5,339.30

Step by Step Solution

1. Step 1: Write the proportion equation
   9,315.52 : 12,857.25 = 5,339.30 : x
2. Step 2: Convert to fraction form
   9,315.52/12,857.25 = 5,339.30/x
3. Step 3: Cross multiply
   9,315.52x = 12,857.25 × 5,339.30
4. Step 4: Simplify right side
   9,315.52x = 68,648,701.58
5. Step 5: Solve for x
   x = 68,648,701.58/9,315.52
6. Step 6: Final answer
   x = 7,369.28