Finding the Third Proportional to 31,920 and 67,290

Step by Step Solution

1. Step 1: Write the proportion equation
   31,920 : 67,290 = 67,290 : x
2. Step 2: Convert to fraction form
   31,920/67,290 = 67,290/x
3. Step 3: Cross multiply
   31,920x = 67,290 × 67,290
4. Step 4: Simplify right side
   31,920x = 4,527,944,100
5. Step 5: Solve for x
   x = 4,527,944,100/31,920
6. Step 6: Final answer
   x = 141,852.89