Finding the Third Proportional to 81,569 and 128,429

Step by Step Solution

1. Step 1: Write the proportion equation
   81,569 : 128,429 = 128,429 : x
2. Step 2: Convert to fraction form
   81,569/128,429 = 128,429/x
3. Step 3: Cross multiply
   81,569x = 128,429 × 128,429
4. Step 4: Simplify right side
   81,569x = 16,494,008,041
5. Step 5: Solve for x
   x = 16,494,008,041/81,569
6. Step 6: Final answer
   x = 202,209.27