Finding the Third Proportional to 307.50 and 408.50

Step by Step Solution

1. Step 1: Write the proportion equation
   307.50 : 408.50 = 408.50 : x
2. Step 2: Convert to fraction form
   307.50/408.50 = 408.50/x
3. Step 3: Cross multiply
   307.50x = 408.50 × 408.50
4. Step 4: Simplify right side
   307.50x = 166,872.25
5. Step 5: Solve for x
   x = 166,872.25/307.50
6. Step 6: Final answer
   x = 542.67