Finding the Third Proportional to 216,716.50 and 287,560

Step by Step Solution

1. Step 1: Write the proportion equation
   216,716.50 : 287,560 = 287,560 : x
2. Step 2: Convert to fraction form
   216,716.50/287,560 = 287,560/x
3. Step 3: Cross multiply
   216,716.50x = 287,560 × 287,560
4. Step 4: Simplify right side
   216,716.50x = 82,690,753,600
5. Step 5: Solve for x
   x = 82,690,753,600/216,716.50
6. Step 6: Final answer
   x = 381,561.87