Finding the Third Proportional to 399,612 and 856,222

Step by Step Solution

1. Step 1: Write the proportion equation
   399,612 : 856,222 = 856,222 : x
2. Step 2: Convert to fraction form
   399,612/856,222 = 856,222/x
3. Step 3: Cross multiply
   399,612x = 856,222 × 856,222
4. Step 4: Simplify right side
   399,612x = 733,116,113,284
5. Step 5: Solve for x
   x = 733,116,113,284/399,612
6. Step 6: Final answer
   x = 1,834,569.82