Finding the Third Proportional to 216,717 and 287,560.50

Step by Step Solution

1. Step 1: Write the proportion equation
   216,717 : 287,560.50 = 287,560.50 : x
2. Step 2: Convert to fraction form
   216,717/287,560.50 = 287,560.50/x
3. Step 3: Cross multiply
   216,717x = 287,560.50 × 287,560.50
4. Step 4: Simplify right side
   216,717x = 82,691,041,160.25
5. Step 5: Solve for x
   x = 82,691,041,160.25/216,717
6. Step 6: Final answer
   x = 381,562.32