Finding the Third Proportional to 287,728 and 435,590

Step by Step Solution

1. Step 1: Write the proportion equation
   287,728 : 435,590 = 435,590 : x
2. Step 2: Convert to fraction form
   287,728/435,590 = 435,590/x
3. Step 3: Cross multiply
   287,728x = 435,590 × 435,590
4. Step 4: Simplify right side
   287,728x = 189,738,648,100
5. Step 5: Solve for x
   x = 189,738,648,100/287,728
6. Step 6: Final answer
   x = 659,437.55