Finding the Third Proportional to 639,412 and 1,400,648

Step by Step Solution

1. Step 1: Write the proportion equation
   639,412 : 1,400,648 = 1,400,648 : x
2. Step 2: Convert to fraction form
   639,412/1,400,648 = 1,400,648/x
3. Step 3: Cross multiply
   639,412x = 1,400,648 × 1,400,648
4. Step 4: Simplify right side
   639,412x = 1,961,814,819,904
5. Step 5: Solve for x
   x = 1,961,814,819,904/639,412
6. Step 6: Final answer
   x = 3,068,154.52