Finding the Fourth Proportional to 9,139.22, 12,612.17 and 5,160.70

Step by Step Solution

1. Step 1: Write the proportion equation
   9,139.22 : 12,612.17 = 5,160.70 : x
2. Step 2: Convert to fraction form
   9,139.22/12,612.17 = 5,160.70/x
3. Step 3: Cross multiply
   9,139.22x = 12,612.17 × 5,160.70
4. Step 4: Simplify right side
   9,139.22x = 65,087,625.72
5. Step 5: Solve for x
   x = 65,087,625.72/9,139.22
6. Step 6: Final answer
   x = 7,121.79