Finding the Third Proportional to 7,831.05 and 12,139.56

Step by Step Solution

1. Step 1: Write the proportion equation
   7,831.05 : 12,139.56 = 12,139.56 : x
2. Step 2: Convert to fraction form
   7,831.05/12,139.56 = 12,139.56/x
3. Step 3: Cross multiply
   7,831.05x = 12,139.56 × 12,139.56
4. Step 4: Simplify right side
   7,831.05x = 147,368,882.85
5. Step 5: Solve for x
   x = 147,368,882.85/7,831.05
6. Step 6: Final answer
   x = 18,818.52