Finding the Third Proportional to 3,947,679 and 8,638,300

Step by Step Solution

1. Step 1: Write the proportion equation
   3,947,679 : 8,638,300 = 8,638,300 : x
2. Step 2: Convert to fraction form
   3,947,679/8,638,300 = 8,638,300/x
3. Step 3: Cross multiply
   3,947,679x = 8,638,300 × 8,638,300
4. Step 4: Simplify right side
   3,947,679x = 74,620,226,890,000
5. Step 5: Solve for x
   x = 74,620,226,890,000/3,947,679
6. Step 6: Final answer
   x = 18,902,303.58