Finding the Third Proportional to 3,987,792 and 8,648,640

Step by Step Solution

1. Step 1: Write the proportion equation
   3,987,792 : 8,648,640 = 8,648,640 : x
2. Step 2: Convert to fraction form
   3,987,792/8,648,640 = 8,648,640/x
3. Step 3: Cross multiply
   3,987,792x = 8,648,640 × 8,648,640
4. Step 4: Simplify right side
   3,987,792x = 74,798,973,849,600
5. Step 5: Solve for x
   x = 74,798,973,849,600/3,987,792
6. Step 6: Final answer
   x = 18,756,989.80