Finding the Third Proportional to 392,492 and 621,810

Step by Step Solution

1. Step 1: Write the proportion equation
   392,492 : 621,810 = 621,810 : x
2. Step 2: Convert to fraction form
   392,492/621,810 = 621,810/x
3. Step 3: Cross multiply
   392,492x = 621,810 × 621,810
4. Step 4: Simplify right side
   392,492x = 386,647,676,100
5. Step 5: Solve for x
   x = 386,647,676,100/392,492
6. Step 6: Final answer
   x = 985,109.70