Finding the Third Proportional to 20,438 and 42,340

Step by Step Solution

1. Step 1: Write the proportion equation
   20,438 : 42,340 = 42,340 : x
2. Step 2: Convert to fraction form
   20,438/42,340 = 42,340/x
3. Step 3: Cross multiply
   20,438x = 42,340 × 42,340
4. Step 4: Simplify right side
   20,438x = 1,792,675,600
5. Step 5: Solve for x
   x = 1,792,675,600/20,438
6. Step 6: Final answer
   x = 87,712.87