Finding the Third Proportional to 30,640 and 67,872

Step by Step Solution

1. Step 1: Write the proportion equation
   30,640 : 67,872 = 67,872 : x
2. Step 2: Convert to fraction form
   30,640/67,872 = 67,872/x
3. Step 3: Cross multiply
   30,640x = 67,872 × 67,872
4. Step 4: Simplify right side
   30,640x = 4,606,608,384
5. Step 5: Solve for x
   x = 4,606,608,384/30,640
6. Step 6: Final answer
   x = 150,346.23