Finding the Third Proportional to 128,530 and 200,116

Step by Step Solution

1. Step 1: Write the proportion equation
   128,530 : 200,116 = 200,116 : x
2. Step 2: Convert to fraction form
   128,530/200,116 = 200,116/x
3. Step 3: Cross multiply
   128,530x = 200,116 × 200,116
4. Step 4: Simplify right side
   128,530x = 40,046,413,456
5. Step 5: Solve for x
   x = 40,046,413,456/128,530
6. Step 6: Final answer
   x = 311,572.50