Finding the Third Proportional to 411.75 and 621.50

Step by Step Solution

1. Step 1: Write the proportion equation
   411.75 : 621.50 = 621.50 : x
2. Step 2: Convert to fraction form
   411.75/621.50 = 621.50/x
3. Step 3: Cross multiply
   411.75x = 621.50 × 621.50
4. Step 4: Simplify right side
   411.75x = 386,262.25
5. Step 5: Solve for x
   x = 386,262.25/411.75
6. Step 6: Final answer
   x = 938.10