Finding the Third Proportional to 309.25 and 424.50

Step by Step Solution

1. Step 1: Write the proportion equation
   309.25 : 424.50 = 424.50 : x
2. Step 2: Convert to fraction form
   309.25/424.50 = 424.50/x
3. Step 3: Cross multiply
   309.25x = 424.50 × 424.50
4. Step 4: Simplify right side
   309.25x = 180,200.25
5. Step 5: Solve for x
   x = 180,200.25/309.25
6. Step 6: Final answer
   x = 582.70