Finding the Third Proportional to 643,613 and 1,388,398

Step by Step Solution

1. Step 1: Write the proportion equation
   643,613 : 1,388,398 = 1,388,398 : x
2. Step 2: Convert to fraction form
   643,613/1,388,398 = 1,388,398/x
3. Step 3: Cross multiply
   643,613x = 1,388,398 × 1,388,398
4. Step 4: Simplify right side
   643,613x = 1,927,649,006,404
5. Step 5: Solve for x
   x = 1,927,649,006,404/643,613
6. Step 6: Final answer
   x = 2,995,043.62