Finding the Third Proportional to 144,819 and 311,431.50

Step by Step Solution

1. Step 1: Write the proportion equation
   144,819 : 311,431.50 = 311,431.50 : x
2. Step 2: Convert to fraction form
   144,819/311,431.50 = 311,431.50/x
3. Step 3: Cross multiply
   144,819x = 311,431.50 × 311,431.50
4. Step 4: Simplify right side
   144,819x = 96,989,579,192.25
5. Step 5: Solve for x
   x = 96,989,579,192.25/144,819
6. Step 6: Final answer
   x = 669,729.66