Finding the Third Proportional to 131,816 and 287,689

Step by Step Solution

1. Step 1: Write the proportion equation
   131,816 : 287,689 = 287,689 : x
2. Step 2: Convert to fraction form
   131,816/287,689 = 287,689/x
3. Step 3: Cross multiply
   131,816x = 287,689 × 287,689
4. Step 4: Simplify right side
   131,816x = 82,764,960,721
5. Step 5: Solve for x
   x = 82,764,960,721/131,816
6. Step 6: Final answer
   x = 627,882.51