Finding the Third Proportional to 400,684 and 620,142

Step by Step Solution

1. Step 1: Write the proportion equation
   400,684 : 620,142 = 620,142 : x
2. Step 2: Convert to fraction form
   400,684/620,142 = 620,142/x
3. Step 3: Cross multiply
   400,684x = 620,142 × 620,142
4. Step 4: Simplify right side
   400,684x = 384,576,100,164
5. Step 5: Solve for x
   x = 384,576,100,164/400,684
6. Step 6: Final answer
   x = 959,798.99