Finding the Fourth Proportional to 9,139.01, 12,612.17 and 5,160.56

Step by Step Solution

1. Step 1: Write the proportion equation
   9,139.01 : 12,612.17 = 5,160.56 : x
2. Step 2: Convert to fraction form
   9,139.01/12,612.17 = 5,160.56/x
3. Step 3: Cross multiply
   9,139.01x = 12,612.17 × 5,160.56
4. Step 4: Simplify right side
   9,139.01x = 65,085,809.86
5. Step 5: Solve for x
   x = 65,085,809.86/9,139.01
6. Step 6: Final answer
   x = 7,121.76