Finding the Third Proportional to 3,879,672 and 8,430,792

Step by Step Solution

1. Step 1: Write the proportion equation
   3,879,672 : 8,430,792 = 8,430,792 : x
2. Step 2: Convert to fraction form
   3,879,672/8,430,792 = 8,430,792/x
3. Step 3: Cross multiply
   3,879,672x = 8,430,792 × 8,430,792
4. Step 4: Simplify right side
   3,879,672x = 71,078,253,747,264
5. Step 5: Solve for x
   x = 71,078,253,747,264/3,879,672
6. Step 6: Final answer
   x = 18,320,686.32