Finding the Third Proportional to 640,920 and 996,384

Step by Step Solution

1. Step 1: Write the proportion equation
   640,920 : 996,384 = 996,384 : x
2. Step 2: Convert to fraction form
   640,920/996,384 = 996,384/x
3. Step 3: Cross multiply
   640,920x = 996,384 × 996,384
4. Step 4: Simplify right side
   640,920x = 992,781,075,456
5. Step 5: Solve for x
   x = 992,781,075,456/640,920
6. Step 6: Final answer
   x = 1,548,993.75