Finding the Third Proportional to 644,140 and 1,399,270

Step by Step Solution

1. Step 1: Write the proportion equation
   644,140 : 1,399,270 = 1,399,270 : x
2. Step 2: Convert to fraction form
   644,140/1,399,270 = 1,399,270/x
3. Step 3: Cross multiply
   644,140x = 1,399,270 × 1,399,270
4. Step 4: Simplify right side
   644,140x = 1,957,956,532,900
5. Step 5: Solve for x
   x = 1,957,956,532,900/644,140
6. Step 6: Final answer
   x = 3,039,644.38