Finding the Third Proportional to 82,506 and 128,688

Step by Step Solution

1. Step 1: Write the proportion equation
   82,506 : 128,688 = 128,688 : x
2. Step 2: Convert to fraction form
   82,506/128,688 = 128,688/x
3. Step 3: Cross multiply
   82,506x = 128,688 × 128,688
4. Step 4: Simplify right side
   82,506x = 16,560,601,344
5. Step 5: Solve for x
   x = 16,560,601,344/82,506
6. Step 6: Final answer
   x = 200,719.96