Finding the Third Proportional to 31,920 and 42,939

Step by Step Solution

1. Step 1: Write the proportion equation
   31,920 : 42,939 = 42,939 : x
2. Step 2: Convert to fraction form
   31,920/42,939 = 42,939/x
3. Step 3: Cross multiply
   31,920x = 42,939 × 42,939
4. Step 4: Simplify right side
   31,920x = 1,843,757,721
5. Step 5: Solve for x
   x = 1,843,757,721/31,920
6. Step 6: Final answer
   x = 57,761.83