Finding the Third Proportional to 142,969.50 and 309,477.50

Step by Step Solution

1. Step 1: Write the proportion equation
   142,969.50 : 309,477.50 = 309,477.50 : x
2. Step 2: Convert to fraction form
   142,969.50/309,477.50 = 309,477.50/x
3. Step 3: Cross multiply
   142,969.50x = 309,477.50 × 309,477.50
4. Step 4: Simplify right side
   142,969.50x = 95,776,323,006.25
5. Step 5: Solve for x
   x = 95,776,323,006.25/142,969.50
6. Step 6: Final answer
   x = 669,907.38