Finding the Third Proportional to 411,424 and 621,510

Step by Step Solution

1. Step 1: Write the proportion equation
   411,424 : 621,510 = 621,510 : x
2. Step 2: Convert to fraction form
   411,424/621,510 = 621,510/x
3. Step 3: Cross multiply
   411,424x = 621,510 × 621,510
4. Step 4: Simplify right side
   411,424x = 386,274,680,100
5. Step 5: Solve for x
   x = 386,274,680,100/411,424
6. Step 6: Final answer
   x = 938,872.50