Finding the Third Proportional to 12,456 and 15,820

Step by Step Solution

1. Step 1: Write the proportion equation
   12,456 : 15,820 = 15,820 : x
2. Step 2: Convert to fraction form
   12,456/15,820 = 15,820/x
3. Step 3: Cross multiply
   12,456x = 15,820 × 15,820
4. Step 4: Simplify right side
   12,456x = 250,272,400
5. Step 5: Solve for x
   x = 250,272,400/12,456
6. Step 6: Final answer
   x = 20,092.52