Finding the Third Proportional to 275,496 and 421,404

Step by Step Solution

1. Step 1: Write the proportion equation
   275,496 : 421,404 = 421,404 : x
2. Step 2: Convert to fraction form
   275,496/421,404 = 421,404/x
3. Step 3: Cross multiply
   275,496x = 421,404 × 421,404
4. Step 4: Simplify right side
   275,496x = 177,581,331,216
5. Step 5: Solve for x
   x = 177,581,331,216/275,496
6. Step 6: Final answer
   x = 644,587.69