Finding the Third Proportional to 148,666.50 and 309,640.50

Step by Step Solution

1. Step 1: Write the proportion equation
   148,666.50 : 309,640.50 = 309,640.50 : x
2. Step 2: Convert to fraction form
   148,666.50/309,640.50 = 309,640.50/x
3. Step 3: Cross multiply
   148,666.50x = 309,640.50 × 309,640.50
4. Step 4: Simplify right side
   148,666.50x = 95,877,239,240.25
5. Step 5: Solve for x
   x = 95,877,239,240.25/148,666.50
6. Step 6: Final answer
   x = 644,914.89