Finding the Third Proportional to 639,978 and 1,382,568

Step by Step Solution

1. Step 1: Write the proportion equation
   639,978 : 1,382,568 = 1,382,568 : x
2. Step 2: Convert to fraction form
   639,978/1,382,568 = 1,382,568/x
3. Step 3: Cross multiply
   639,978x = 1,382,568 × 1,382,568
4. Step 4: Simplify right side
   639,978x = 1,911,494,274,624
5. Step 5: Solve for x
   x = 1,911,494,274,624/639,978
6. Step 6: Final answer
   x = 2,986,812.48