Finding the Third Proportional to 128,606 and 200,270

Step by Step Solution

1. Step 1: Write the proportion equation
   128,606 : 200,270 = 200,270 : x
2. Step 2: Convert to fraction form
   128,606/200,270 = 200,270/x
3. Step 3: Cross multiply
   128,606x = 200,270 × 200,270
4. Step 4: Simplify right side
   128,606x = 40,108,072,900
5. Step 5: Solve for x
   x = 40,108,072,900/128,606
6. Step 6: Final answer
   x = 311,867.82