Finding the Third Proportional to 558 and 613.50

Step by Step Solution

1. Step 1: Write the proportion equation
   558 : 613.50 = 613.50 : x
2. Step 2: Convert to fraction form
   558/613.50 = 613.50/x
3. Step 3: Cross multiply
   558x = 613.50 × 613.50
4. Step 4: Simplify right side
   558x = 376,382.25
5. Step 5: Solve for x
   x = 376,382.25/558
6. Step 6: Final answer
   x = 674.52