Finding the Third Proportional to 639,348 and 1,378,308

Step by Step Solution

1. Step 1: Write the proportion equation
   639,348 : 1,378,308 = 1,378,308 : x
2. Step 2: Convert to fraction form
   639,348/1,378,308 = 1,378,308/x
3. Step 3: Cross multiply
   639,348x = 1,378,308 × 1,378,308
4. Step 4: Simplify right side
   639,348x = 1,899,732,942,864
5. Step 5: Solve for x
   x = 1,899,732,942,864/639,348
6. Step 6: Final answer
   x = 2,971,359.80