Finding the Third Proportional to 639,748 and 921,606

Step by Step Solution

1. Step 1: Write the proportion equation
   639,748 : 921,606 = 921,606 : x
2. Step 2: Convert to fraction form
   639,748/921,606 = 921,606/x
3. Step 3: Cross multiply
   639,748x = 921,606 × 921,606
4. Step 4: Simplify right side
   639,748x = 849,357,619,236
5. Step 5: Solve for x
   x = 849,357,619,236/639,748
6. Step 6: Final answer
   x = 1,327,644.04