Finding the Third Proportional to 200,978 and 418,494

Step by Step Solution

1. Step 1: Write the proportion equation
   200,978 : 418,494 = 418,494 : x
2. Step 2: Convert to fraction form
   200,978/418,494 = 418,494/x
3. Step 3: Cross multiply
   200,978x = 418,494 × 418,494
4. Step 4: Simplify right side
   200,978x = 175,137,228,036
5. Step 5: Solve for x
   x = 175,137,228,036/200,978
6. Step 6: Final answer
   x = 871,424.87