Finding the Third Proportional to 639,200 and 1,420,288

Step by Step Solution

1. Step 1: Write the proportion equation
   639,200 : 1,420,288 = 1,420,288 : x
2. Step 2: Convert to fraction form
   639,200/1,420,288 = 1,420,288/x
3. Step 3: Cross multiply
   639,200x = 1,420,288 × 1,420,288
4. Step 4: Simplify right side
   639,200x = 2,017,218,002,944
5. Step 5: Solve for x
   x = 2,017,218,002,944/639,200
6. Step 6: Final answer
   x = 3,155,847.94