Finding the Third Proportional to 20,456 and 42,219

Step by Step Solution

1. Step 1: Write the proportion equation
   20,456 : 42,219 = 42,219 : x
2. Step 2: Convert to fraction form
   20,456/42,219 = 42,219/x
3. Step 3: Cross multiply
   20,456x = 42,219 × 42,219
4. Step 4: Simplify right side
   20,456x = 1,782,443,961
5. Step 5: Solve for x
   x = 1,782,443,961/20,456
6. Step 6: Final answer
   x = 87,135.51