Finding the Third Proportional to 309,417 and 492,342.75

Step by Step Solution

1. Step 1: Write the proportion equation
   309,417 : 492,342.75 = 492,342.75 : x
2. Step 2: Convert to fraction form
   309,417/492,342.75 = 492,342.75/x
3. Step 3: Cross multiply
   309,417x = 492,342.75 × 492,342.75
4. Step 4: Simplify right side
   309,417x = 242,401,383,477.56
5. Step 5: Solve for x
   x = 242,401,383,477.56/309,417
6. Step 6: Final answer
   x = 783,413.27