Finding the Third Proportional to 128,401.50 and 309,330

Step by Step Solution

1. Step 1: Write the proportion equation
   128,401.50 : 309,330 = 309,330 : x
2. Step 2: Convert to fraction form
   128,401.50/309,330 = 309,330/x
3. Step 3: Cross multiply
   128,401.50x = 309,330 × 309,330
4. Step 4: Simplify right side
   128,401.50x = 95,685,048,900
5. Step 5: Solve for x
   x = 95,685,048,900/128,401.50
6. Step 6: Final answer
   x = 745,201.96