Finding the Third Proportional to 216,757 and 287,686.50

Step by Step Solution

1. Step 1: Write the proportion equation
   216,757 : 287,686.50 = 287,686.50 : x
2. Step 2: Convert to fraction form
   216,757/287,686.50 = 287,686.50/x
3. Step 3: Cross multiply
   216,757x = 287,686.50 × 287,686.50
4. Step 4: Simplify right side
   216,757x = 82,763,522,282.25
5. Step 5: Solve for x
   x = 82,763,522,282.25/216,757
6. Step 6: Final answer
   x = 381,826.30