Finding the Third Proportional to 265,636 and 399,456

Step by Step Solution

1. Step 1: Write the proportion equation
   265,636 : 399,456 = 399,456 : x
2. Step 2: Convert to fraction form
   265,636/399,456 = 399,456/x
3. Step 3: Cross multiply
   265,636x = 399,456 × 399,456
4. Step 4: Simplify right side
   265,636x = 159,565,095,936
5. Step 5: Solve for x
   x = 159,565,095,936/265,636
6. Step 6: Final answer
   x = 600,690.78