Finding the Third Proportional to 31,776 and 67,920

Step by Step Solution

1. Step 1: Write the proportion equation
   31,776 : 67,920 = 67,920 : x
2. Step 2: Convert to fraction form
   31,776/67,920 = 67,920/x
3. Step 3: Cross multiply
   31,776x = 67,920 × 67,920
4. Step 4: Simplify right side
   31,776x = 4,613,126,400
5. Step 5: Solve for x
   x = 4,613,126,400/31,776
6. Step 6: Final answer
   x = 145,176.44