Finding the Third Proportional to 20,799 and 42,570

Step by Step Solution

1. Step 1: Write the proportion equation
   20,799 : 42,570 = 42,570 : x
2. Step 2: Convert to fraction form
   20,799/42,570 = 42,570/x
3. Step 3: Cross multiply
   20,799x = 42,570 × 42,570
4. Step 4: Simplify right side
   20,799x = 1,812,204,900
5. Step 5: Solve for x
   x = 1,812,204,900/20,799
6. Step 6: Final answer
   x = 87,129.42