Finding the Third Proportional to 31,418 and 67,420

Step by Step Solution

1. Step 1: Write the proportion equation
   31,418 : 67,420 = 67,420 : x
2. Step 2: Convert to fraction form
   31,418/67,420 = 67,420/x
3. Step 3: Cross multiply
   31,418x = 67,420 × 67,420
4. Step 4: Simplify right side
   31,418x = 4,545,456,400
5. Step 5: Solve for x
   x = 4,545,456,400/31,418
6. Step 6: Final answer
   x = 144,676.82