Finding the Third Proportional to 3,969,638 and 8,611,432

Step by Step Solution

1. Step 1: Write the proportion equation
   3,969,638 : 8,611,432 = 8,611,432 : x
2. Step 2: Convert to fraction form
   3,969,638/8,611,432 = 8,611,432/x
3. Step 3: Cross multiply
   3,969,638x = 8,611,432 × 8,611,432
4. Step 4: Simplify right side
   3,969,638x = 74,156,761,090,624
5. Step 5: Solve for x
   x = 74,156,761,090,624/3,969,638
6. Step 6: Final answer
   x = 18,680,988.31