Finding the Third Proportional to 12,020 and 15,642

Step by Step Solution

1. Step 1: Write the proportion equation
   12,020 : 15,642 = 15,642 : x
2. Step 2: Convert to fraction form
   12,020/15,642 = 15,642/x
3. Step 3: Cross multiply
   12,020x = 15,642 × 15,642
4. Step 4: Simplify right side
   12,020x = 244,672,164
5. Step 5: Solve for x
   x = 244,672,164/12,020
6. Step 6: Final answer
   x = 20,355.42