Finding the Third Proportional to 4,218,806 and 8,736,688

Step by Step Solution

1. Step 1: Write the proportion equation
   4,218,806 : 8,736,688 = 8,736,688 : x
2. Step 2: Convert to fraction form
   4,218,806/8,736,688 = 8,736,688/x
3. Step 3: Cross multiply
   4,218,806x = 8,736,688 × 8,736,688
4. Step 4: Simplify right side
   4,218,806x = 76,329,717,209,344
5. Step 5: Solve for x
   x = 76,329,717,209,344/4,218,806
6. Step 6: Final answer
   x = 18,092,729.84