Finding the Third Proportional to 13,678 and 21,428

Step by Step Solution

1. Step 1: Write the proportion equation
   13,678 : 21,428 = 21,428 : x
2. Step 2: Convert to fraction form
   13,678/21,428 = 21,428/x
3. Step 3: Cross multiply
   13,678x = 21,428 × 21,428
4. Step 4: Simplify right side
   13,678x = 459,159,184
5. Step 5: Solve for x
   x = 459,159,184/13,678
6. Step 6: Final answer
   x = 33,569.18