Finding the Third Proportional to 31,381 and 72,621

Step by Step Solution

1. Step 1: Write the proportion equation
   31,381 : 72,621 = 72,621 : x
2. Step 2: Convert to fraction form
   31,381/72,621 = 72,621/x
3. Step 3: Cross multiply
   31,381x = 72,621 × 72,621
4. Step 4: Simplify right side
   31,381x = 5,273,809,641
5. Step 5: Solve for x
   x = 5,273,809,641/31,381
6. Step 6: Final answer
   x = 168,057.41