Finding the Third Proportional to 209,857.50 and 458,131.78

Step by Step Solution

1. Step 1: Write the proportion equation
   209,857.50 : 458,131.78 = 458,131.78 : x
2. Step 2: Convert to fraction form
   209,857.50/458,131.78 = 458,131.78/x
3. Step 3: Cross multiply
   209,857.50x = 458,131.78 × 458,131.78
4. Step 4: Simplify right side
   209,857.50x = 209,884,728,991.30
5. Step 5: Solve for x
   x = 209,884,728,991.30/209,857.50
6. Step 6: Final answer
   x = 1,000,129.75