Finding the Third Proportional to 639,856 and 1,385,696

Step by Step Solution

1. Step 1: Write the proportion equation
   639,856 : 1,385,696 = 1,385,696 : x
2. Step 2: Convert to fraction form
   639,856/1,385,696 = 1,385,696/x
3. Step 3: Cross multiply
   639,856x = 1,385,696 × 1,385,696
4. Step 4: Simplify right side
   639,856x = 1,920,153,404,416
5. Step 5: Solve for x
   x = 1,920,153,404,416/639,856
6. Step 6: Final answer
   x = 3,000,914.90