Finding the Third Proportional to 31,086 and 67,689

Step by Step Solution

1. Step 1: Write the proportion equation
   31,086 : 67,689 = 67,689 : x
2. Step 2: Convert to fraction form
   31,086/67,689 = 67,689/x
3. Step 3: Cross multiply
   31,086x = 67,689 × 67,689
4. Step 4: Simplify right side
   31,086x = 4,581,800,721
5. Step 5: Solve for x
   x = 4,581,800,721/31,086
6. Step 6: Final answer
   x = 147,391.13