Finding the Third Proportional to 639,266 and 1,389,124

Step by Step Solution

1. Step 1: Write the proportion equation
   639,266 : 1,389,124 = 1,389,124 : x
2. Step 2: Convert to fraction form
   639,266/1,389,124 = 1,389,124/x
3. Step 3: Cross multiply
   639,266x = 1,389,124 × 1,389,124
4. Step 4: Simplify right side
   639,266x = 1,929,665,487,376
5. Step 5: Solve for x
   x = 1,929,665,487,376/639,266
6. Step 6: Final answer
   x = 3,018,564.24