Finding the Third Proportional to 99,780 and 210,799

Step by Step Solution

1. Step 1: Write the proportion equation
   99,780 : 210,799 = 210,799 : x
2. Step 2: Convert to fraction form
   99,780/210,799 = 210,799/x
3. Step 3: Cross multiply
   99,780x = 210,799 × 210,799
4. Step 4: Simplify right side
   99,780x = 44,436,218,401
5. Step 5: Solve for x
   x = 44,436,218,401/99,780
6. Step 6: Final answer
   x = 445,341.94