Finding the Third Proportional to 411.50 and 654.25

Step by Step Solution

1. Step 1: Write the proportion equation
   411.50 : 654.25 = 654.25 : x
2. Step 2: Convert to fraction form
   411.50/654.25 = 654.25/x
3. Step 3: Cross multiply
   411.50x = 654.25 × 654.25
4. Step 4: Simplify right side
   411.50x = 428,043.06
5. Step 5: Solve for x
   x = 428,043.06/411.50
6. Step 6: Final answer
   x = 1,040.20