Finding the Third Proportional to 8,686.50 and 20,490.75

Step by Step Solution

1. Step 1: Write the proportion equation
   8,686.50 : 20,490.75 = 20,490.75 : x
2. Step 2: Convert to fraction form
   8,686.50/20,490.75 = 20,490.75/x
3. Step 3: Cross multiply
   8,686.50x = 20,490.75 × 20,490.75
4. Step 4: Simplify right side
   8,686.50x = 419,870,835.56
5. Step 5: Solve for x
   x = 419,870,835.56/8,686.50
6. Step 6: Final answer
   x = 48,336.02