Finding the Fourth Proportional to 9,118.28, 12,583.47 and 5,139.15

Step by Step Solution

1. Step 1: Write the proportion equation
   9,118.28 : 12,583.47 = 5,139.15 : x
2. Step 2: Convert to fraction form
   9,118.28/12,583.47 = 5,139.15/x
3. Step 3: Cross multiply
   9,118.28x = 12,583.47 × 5,139.15
4. Step 4: Simplify right side
   9,118.28x = 64,668,339.85
5. Step 5: Solve for x
   x = 64,668,339.85/9,118.28
6. Step 6: Final answer
   x = 7,092.17