Finding the Third Proportional to 290,415.38 and 427,057.31

Step by Step Solution

1. Step 1: Write the proportion equation
   290,415.38 : 427,057.31 = 427,057.31 : x
2. Step 2: Convert to fraction form
   290,415.38/427,057.31 = 427,057.31/x
3. Step 3: Cross multiply
   290,415.38x = 427,057.31 × 427,057.31
4. Step 4: Simplify right side
   290,415.38x = 182,377,948,159.72
5. Step 5: Solve for x
   x = 182,377,948,159.72/290,415.38
6. Step 6: Final answer
   x = 627,989.99