Finding the Third Proportional to 258,788 and 411,510

Step by Step Solution

1. Step 1: Write the proportion equation
   258,788 : 411,510 = 411,510 : x
2. Step 2: Convert to fraction form
   258,788/411,510 = 411,510/x
3. Step 3: Cross multiply
   258,788x = 411,510 × 411,510
4. Step 4: Simplify right side
   258,788x = 169,340,480,100
5. Step 5: Solve for x
   x = 169,340,480,100/258,788
6. Step 6: Final answer
   x = 654,359.86