Finding the Third Proportional to 331,221 and 718,453.50

Step by Step Solution

1. Step 1: Write the proportion equation
   331,221 : 718,453.50 = 718,453.50 : x
2. Step 2: Convert to fraction form
   331,221/718,453.50 = 718,453.50/x
3. Step 3: Cross multiply
   331,221x = 718,453.50 × 718,453.50
4. Step 4: Simplify right side
   331,221x = 516,175,431,662.25
5. Step 5: Solve for x
   x = 516,175,431,662.25/331,221
6. Step 6: Final answer
   x = 1,558,401.89