Finding the Third Proportional to 128,687 and 196,857.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,687 : 196,857.50 = 196,857.50 : x
2. Step 2: Convert to fraction form
   128,687/196,857.50 = 196,857.50/x
3. Step 3: Cross multiply
   128,687x = 196,857.50 × 196,857.50
4. Step 4: Simplify right side
   128,687x = 38,752,875,306.25
5. Step 5: Solve for x
   x = 38,752,875,306.25/128,687
6. Step 6: Final answer
   x = 301,140.56