Finding the Third Proportional to 644,140 and 1,399,272

Step by Step Solution

1. Step 1: Write the proportion equation
   644,140 : 1,399,272 = 1,399,272 : x
2. Step 2: Convert to fraction form
   644,140/1,399,272 = 1,399,272/x
3. Step 3: Cross multiply
   644,140x = 1,399,272 × 1,399,272
4. Step 4: Simplify right side
   644,140x = 1,957,962,129,984
5. Step 5: Solve for x
   x = 1,957,962,129,984/644,140
6. Step 6: Final answer
   x = 3,039,653.07