Finding the Third Proportional to 287,408 and 435,087

Step by Step Solution

1. Step 1: Write the proportion equation
   287,408 : 435,087 = 435,087 : x
2. Step 2: Convert to fraction form
   287,408/435,087 = 435,087/x
3. Step 3: Cross multiply
   287,408x = 435,087 × 435,087
4. Step 4: Simplify right side
   287,408x = 189,300,697,569
5. Step 5: Solve for x
   x = 189,300,697,569/287,408
6. Step 6: Final answer
   x = 658,647.98