Finding the Third Proportional to 129,308 and 200,688

Step by Step Solution

1. Step 1: Write the proportion equation
   129,308 : 200,688 = 200,688 : x
2. Step 2: Convert to fraction form
   129,308/200,688 = 200,688/x
3. Step 3: Cross multiply
   129,308x = 200,688 × 200,688
4. Step 4: Simplify right side
   129,308x = 40,275,673,344
5. Step 5: Solve for x
   x = 40,275,673,344/129,308
6. Step 6: Final answer
   x = 311,470.86