Finding the Third Proportional to 20,520 and 30,780

Step by Step Solution

1. Step 1: Write the proportion equation
   20,520 : 30,780 = 30,780 : x
2. Step 2: Convert to fraction form
   20,520/30,780 = 30,780/x
3. Step 3: Cross multiply
   20,520x = 30,780 × 30,780
4. Step 4: Simplify right side
   20,520x = 947,408,400
5. Step 5: Solve for x
   x = 947,408,400/20,520
6. Step 6: Final answer
   x = 46,170