Finding the Third Proportional to 287,055 and 620,040

Step by Step Solution

1. Step 1: Write the proportion equation
   287,055 : 620,040 = 620,040 : x
2. Step 2: Convert to fraction form
   287,055/620,040 = 620,040/x
3. Step 3: Cross multiply
   287,055x = 620,040 × 620,040
4. Step 4: Simplify right side
   287,055x = 384,449,601,600
5. Step 5: Solve for x
   x = 384,449,601,600/287,055
6. Step 6: Final answer
   x = 1,339,288.99