Finding the Third Proportional to 399,870 and 603,936

Step by Step Solution

1. Step 1: Write the proportion equation
   399,870 : 603,936 = 603,936 : x
2. Step 2: Convert to fraction form
   399,870/603,936 = 603,936/x
3. Step 3: Cross multiply
   399,870x = 603,936 × 603,936
4. Step 4: Simplify right side
   399,870x = 364,738,692,096
5. Step 5: Solve for x
   x = 364,738,692,096/399,870
6. Step 6: Final answer
   x = 912,143.18