Finding the Third Proportional to 128,608 and 200,274

Step by Step Solution

1. Step 1: Write the proportion equation
   128,608 : 200,274 = 200,274 : x
2. Step 2: Convert to fraction form
   128,608/200,274 = 200,274/x
3. Step 3: Cross multiply
   128,608x = 200,274 × 200,274
4. Step 4: Simplify right side
   128,608x = 40,109,675,076
5. Step 5: Solve for x
   x = 40,109,675,076/128,608
6. Step 6: Final answer
   x = 311,875.43