Finding the Third Proportional to 321,978 and 699,282

Step by Step Solution

1. Step 1: Write the proportion equation
   321,978 : 699,282 = 699,282 : x
2. Step 2: Convert to fraction form
   321,978/699,282 = 699,282/x
3. Step 3: Cross multiply
   321,978x = 699,282 × 699,282
4. Step 4: Simplify right side
   321,978x = 488,995,315,524
5. Step 5: Solve for x
   x = 488,995,315,524/321,978
6. Step 6: Final answer
   x = 1,518,722.76