Finding the Third Proportional to 13,728 and 21,240

Step by Step Solution

1. Step 1: Write the proportion equation
   13,728 : 21,240 = 21,240 : x
2. Step 2: Convert to fraction form
   13,728/21,240 = 21,240/x
3. Step 3: Cross multiply
   13,728x = 21,240 × 21,240
4. Step 4: Simplify right side
   13,728x = 451,137,600
5. Step 5: Solve for x
   x = 451,137,600/13,728
6. Step 6: Final answer
   x = 32,862.59