Finding the Third Proportional to 640,128 and 1,395,456

Step by Step Solution

1. Step 1: Write the proportion equation
   640,128 : 1,395,456 = 1,395,456 : x
2. Step 2: Convert to fraction form
   640,128/1,395,456 = 1,395,456/x
3. Step 3: Cross multiply
   640,128x = 1,395,456 × 1,395,456
4. Step 4: Simplify right side
   640,128x = 1,947,297,447,936
5. Step 5: Solve for x
   x = 1,947,297,447,936/640,128
6. Step 6: Final answer
   x = 3,042,043.85