Finding the Third Proportional to 400,682 and 620,139

Step by Step Solution

1. Step 1: Write the proportion equation
   400,682 : 620,139 = 620,139 : x
2. Step 2: Convert to fraction form
   400,682/620,139 = 620,139/x
3. Step 3: Cross multiply
   400,682x = 620,139 × 620,139
4. Step 4: Simplify right side
   400,682x = 384,572,379,321
5. Step 5: Solve for x
   x = 384,572,379,321/400,682
6. Step 6: Final answer
   x = 959,794.50