Finding the Third Proportional to 142,821 and 313,144.50

Step by Step Solution

1. Step 1: Write the proportion equation
   142,821 : 313,144.50 = 313,144.50 : x
2. Step 2: Convert to fraction form
   142,821/313,144.50 = 313,144.50/x
3. Step 3: Cross multiply
   142,821x = 313,144.50 × 313,144.50
4. Step 4: Simplify right side
   142,821x = 98,059,477,880.25
5. Step 5: Solve for x
   x = 98,059,477,880.25/142,821
6. Step 6: Final answer
   x = 686,590.05