Finding the Third Proportional to 3,937,430 and 8,420,836

Step by Step Solution

1. Step 1: Write the proportion equation
   3,937,430 : 8,420,836 = 8,420,836 : x
2. Step 2: Convert to fraction form
   3,937,430/8,420,836 = 8,420,836/x
3. Step 3: Cross multiply
   3,937,430x = 8,420,836 × 8,420,836
4. Step 4: Simplify right side
   3,937,430x = 70,910,478,938,896
5. Step 5: Solve for x
   x = 70,910,478,938,896/3,937,430
6. Step 6: Final answer
   x = 18,009,330.69