Finding the Third Proportional to 399,434 and 869,404

Step by Step Solution

1. Step 1: Write the proportion equation
   399,434 : 869,404 = 869,404 : x
2. Step 2: Convert to fraction form
   399,434/869,404 = 869,404/x
3. Step 3: Cross multiply
   399,434x = 869,404 × 869,404
4. Step 4: Simplify right side
   399,434x = 755,863,315,216
5. Step 5: Solve for x
   x = 755,863,315,216/399,434
6. Step 6: Final answer
   x = 1,892,335.94