Finding the Third Proportional to 3,969,639 and 8,611,416

Step by Step Solution

1. Step 1: Write the proportion equation
   3,969,639 : 8,611,416 = 8,611,416 : x
2. Step 2: Convert to fraction form
   3,969,639/8,611,416 = 8,611,416/x
3. Step 3: Cross multiply
   3,969,639x = 8,611,416 × 8,611,416
4. Step 4: Simplify right side
   3,969,639x = 74,156,485,525,056
5. Step 5: Solve for x
   x = 74,156,485,525,056/3,969,639
6. Step 6: Final answer
   x = 18,680,914.19