Finding the Third Proportional to 82,515 and 128,700

Step by Step Solution

1. Step 1: Write the proportion equation
   82,515 : 128,700 = 128,700 : x
2. Step 2: Convert to fraction form
   82,515/128,700 = 128,700/x
3. Step 3: Cross multiply
   82,515x = 128,700 × 128,700
4. Step 4: Simplify right side
   82,515x = 16,563,690,000
5. Step 5: Solve for x
   x = 16,563,690,000/82,515
6. Step 6: Final answer
   x = 200,735.50