Finding the Third Proportional to 643,623 and 1,388,412

Step by Step Solution

1. Step 1: Write the proportion equation
   643,623 : 1,388,412 = 1,388,412 : x
2. Step 2: Convert to fraction form
   643,623/1,388,412 = 1,388,412/x
3. Step 3: Cross multiply
   643,623x = 1,388,412 × 1,388,412
4. Step 4: Simplify right side
   643,623x = 1,927,687,881,744
5. Step 5: Solve for x
   x = 1,927,687,881,744/643,623
6. Step 6: Final answer
   x = 2,995,057.48